Introduction to encrypted Internet chat

In the middle of a discussion about IRC chat, I mentioned SILC, which apparently, quite a few people haven't heard about yet. It's not terribly surprising. Once quite popular, IRC is now a fringe communications platform in the wake of instant messaging. If IRC users represent the fringe of Internet society, then SILC users are the consummate outliers.

This post was made mostly to go along with a quick presentation I'm doing for Cowtown Computer Congress this evening. This is a quick and dirty rough draft that will likely be edited for speling and grammer err0rz.

SILC is Secure Internet Live Conferencing, and it borrows many things directly from Internet Relay Chat, fixing some of the weaknesses of IRC by using certificates, key exchange algorithms, digital signatures and encrypted connections. The end result is a chat platform capable of being used by groups or one-on-one communication where you can be absolutely sure you are communicating with the person you think you're communicating with. With the appropriate measures, you can also be certain that messages can't be trivially intercepted or forged by outsiders, even if the SILC server or network has been compromised. When talking in public groups (equivalent to IRC channels), only those in the group can see the messages due to a shared session key. People sniffing your local network segment won't know what's being said or with whom you're communicating.

While on the topic of encrypted chat, I'll also discuss Off-The-Record, a cryptographic plug-in that sits on top of certain instant messaging platforms (like AIM) by sending strong-crypto messsages over base64-encoded strings between users. To this end, it's usually easy for someone monitoring the network to tell with whom you're communicating, but nearly impossible to determine the actual contents of said communication.

Of course, some of these things have been recently been addressed, albeit not nearly as thoroughly, by using SSL/TLS. Several modern IM protocols rely on SSL/TLS, and certain IRC implementations also can use SSL now. These are beyond the scope of this article, but worth mentioning in passing.

There are two actively-developed clients that I will cover:

• A SILC plugin for irssi, a popular IRC client, which works best on Linux
• Native SILC support in Pidgin IM, which works on Mac OS X, Linux and Windows. Pidgin plugins for Off-The-Record exist for Mac OS X, Linux and Windows as well.
  

Irssi
Irssi is my favorite IRC client. It's a curses-based program that runs in the terminal. The SILC plugin for irssi can be found in many package repositories. For example, installing it (and all dependencies, including irssi itself) in Ubuntu is as easy as:

$ sudo apt-get install irssi-plugin-silc



If you're familiar with IRC, it uses some familiar derivatives of commands:

Load the SILC plugin, prompts for your private key passphrase
/load silc

Connect to a SILC server
/connect -silcnet SILCnet [silc-server]

Join a group (or channel)
/join [group]

Grant operator status to a user in a group you control
/cumode [group] +o [user]

Send a one-on-one message to another user
/msg [user] [message]

To compare, this is a screen shot of captured traffic from plain-text IRC, followed by one from SILC.




Pidgin
Pidgin is a cross platform open source chat application that natively supports all the major Instant Messaging protocols, including AIM, SILC and IRC. Once you've added a SILC server (via Accounts), you simply go to the Buddy List and select "Add chat" to join a group.


Off-The-Record
Adium, the Pidgin port for Mac OS X comes with OTR built right in!


Installing on Ubuntu is easy, as this will install Pidgin and the OTR plugin and all dependencies.
$ sudo apt-get install pidgin-otr

To get it up and running on Windows, first install Pidgin, then run the OTR plugin installer.

On Linux and Windows, you'll have to enable the plugin and generate a key before you can use it.




And then, once you initiate a chat with someone who also has OTR, you will need to verify their key. The best way to do this is in person or over a trusted communications platform. If you know their voice well enough, a phone call would probably work just fine.


Although AIM uses SSL by default these days, it's not uncommon to see AIM go across the wire in cleartext. Here's a screen shot comparing packet captures from a cleartext AIM session and one using OTR. You can't see it in the screen shots because of how large the OTR message is, but the OTR session only encrypts the message content itself. You can still see the names of the parties communicating.




That's all I've got for now.

Is Firefox shipping with a Rogue SSL CA?

This discussion came across my radar this morning via Hacker News.

Details are still being hashed out, but the fact remains that there is a Root CA shipping with Firefox that no one can account for. I recommend removing "RSA Security 1024 V3", but not "RSA Security 2048 V3" (which actually shows up on RSA's Audit Statement [PDF warning])

Hopefully, this is just one that's fallen into disuse over the last 8 years, and not a case where someone slipped a CA into the distribution and attempted to camouflage it by making it look similar to an existing CA.

Update from Kathleen Wilson (thanks to gregms):

I have received email from official representatives of RSA confirming
that RSA did indeed create the "RSA Security 1024 V3" root certificate
that is currently included in NSS (Netscape/Mozilla) and also in Apple's
root cert store.

Smoking (Cloud) Crack

Making waves in the infosec blogosphere today: Cracking a PGP-protected ZIP file using Amazon's EC2 cloud computing infrastructure. There's some interesting data presented, especially when extrapolating the cost involved with breaking the encryption. There are a number of flaws in the write-up, though. I'll take it to task here, then cover some of the important and extremely valid points that the write-up did make.

This was a brute force password attack

If you happen to intercept PGP communication between two people, there's no password in the world that can decrypt it. The password (or passphrase) only unlocks the secret key, which is actually needed to decrypt the communication. If you don't have the secret key, your options for recovering the encrypted content are mathematically tantamount to nil. If you do have someone's secret key file, that person did something very wrong and stupid. The proper thing for that person to do when there's reason to believe their secret key is compromised: revoke the key, and tell everyone that the key has been compromised! I cover some of this in my GPG Key Management & Signing Article. Some Cloud Crack™ was being smoked by someone, as the crackers had access to the secret key, which shouldn't ever happen.

It doesn't always cost millions of dollars for CPU cycles.

Ages ago, my friend Bob had distributed.net agents running on 90% of the lab computers at the college he attended. These were all fairly new computers, too. Have physical access to 100 computers? You can probably spawn 100 instances of EDPR. For free. As in free beer. Okay, free beer plus the cost of the EDPR entitlements.

Plain old CPU cycles are so '90s. These days, we have the ability to harness compute power of FPGAs, and thanks to things like the CUDA architecture, Graphics Processing Units (GPUs) as well. These technologies take traditional CPU cycle density and cost paradigms and turn them inside out. It doesn't come cheap, but it's surprisingly affordable, more efficient, and denser than building racks of x86 machines. The author spoke of a corporate espionage scenario, with budgets of around $1M to compromise a competitor's data. $1M would go a very long way with FPGA or CUDA technology.

Finally, there's the black-hat side. Botnet zombies are cheap. Spammers, scammers, and malware tycoons know this. If you have some skills, free time and lack a moral compass, you can roll your own botnet or hijack someone else's botnet zombies for free. Again, as in free beer. Don't think it happens? Don't kid yourself.

Brute Forcing is real

While brute force doesn't work against PGP in a perfect world, it does work almost anywhere a password is involved, and the numbers don't lie. An attack like this against an encrypted TrueCrypt volume, for example, would be bone-chilling if it succeeded. Normal "protected" zip files, documents, and accounts are vulnerable, and there are multiple tools to brute force almost any kind of password.

Longer is better, for the most part

Long, simple passphrases win out over short, complex passwords when it comes to brute force. Still, if you use something that's easy to guess, like the first sentence of the book currently marked as your favorite on some social networking site, you might be in trouble. The ways you choose, guard, and use your passwords are parts of a very complex problem that not even the best in the industry can agree on a solution for. Good luck with that.

If all else fails, there's always rubber-hose cryptanalysis. Remember, you can't hide secrets from the future with math.

Encryption Technologies to Avoid

This is intended to be a supplementary information resource on cryptographic best practices. In this article I will cover some cryptographic algorithms with known flaws and some alternatives.

=== ToC =============

1. Introduction

2. Known insecure encryption technologies

3. Alternatives

4. Informative resources

====================

1. Introduction

Security is not the black box on your desktop or network. It it isn't a graphic you put on your website saying that the site is secure because you have a firewall. Security is the constant dialog between you and the other people in your organization on how to best secure the information which you have been entrusted with.

To that end I would like to bring up some technologies which we should avoid or migrate away from at our earliest opportunity.

2. Known insecure encryption technologies.

• DES - DES has been broken for quite a while.
• MD5
  
• SHA1

DES stands for Digital Encryption Standard, it was developed by IBM in 1972. Originally the team at IBM was said to have specified a 128 bit algorithm but was later asked by the NSA to reduce it to 64bit and later 56. This is refuted by government probes, then the insecurity was verified by cryptanalysis and later interviews with the people involved in the project and in de-classified documents.

MD5 is a hashing algorithm designed by Professor Ronald Rivest of MIT. There was research which theorized collisions in the algorithm in 1993, more collisions in 1996 and finally an algorithm was created to generate collisions in 2005 using a large cluster and in 2006 the algorithm was perfected only requiring a single computer.

The SHA cryptographic functions were written by the NSA in 1992. In 2005 flaws were found in the SHA-1 algorithm, although these flaws are yet to be exploited it was decided to move on to a different algorithm.

Things that were never a good idea to begin with:

• Character replacement ex. ROT13, Caesar Cipher
  
• XOR encryption against a trivial key
  
• base64 encoding (or any other encoding)

Character replacement, encoding and XOR are trivial to decrypt/decode. In the case of encoding or replacement, these are easily detected because the structure of the message itself isn't changed. XOR is computationally simple so brute forcing, frequency analysis and other methods can be used to decipher it. Using XOR against a very complex non-repeating one-time pad can offer quite a bit of security as long as strict protocol is followed in handling cleartext and the pad itself.

3. Alternatives
DES users should consider using AES, preferably one of the versions with larger key sizes 256 or 512. MD5 and SHA1 users should consider using the SHA-2 algorithm which are considered to be safe for now. There is an on-going contest to decide what algorithm to use for the new SHA-3 standard.

Many SSL certificates are signed using a MD5 algorithm. This creates the possibility of forging ssl certificates. In addition there was a bad patch to the OpenSSH package in Debian Linux in 2008 which made certificates generated by the affected server insecure. There is a firefox extension which will warn you if the certificate is vulnerable.

4. Informative resources

Wikipedia.org (Accessed April 26, 2009)

• http://en.wikipedia.org/wiki/Advanced_Encryption_Standard
• http://en.wikipedia.org/wiki/Data_Encryption_Standard
• http://en.wikipedia.org/wiki/MD5
• http://en.wikipedia.org/wiki/SHA1

Anka, Márton. "SSL Black List." (Accessed April 26, 2009)
http://www.codefromthe70s.org/sslblacklist.aspx

See also:

• GPG Part 1
• GPG Part 2
• Rubber Hose Cryptanalysis
• Steganography
• Encrypted filesystem images
• Cryptography fun with newLISP
  

GPG Part 2: Key Revocation

Almost immediately after posting the last article on creating, distributing, and signing GPG keys, a few good questions started flowing in over Twitter. The questions were basically about "what if I lose my secret key?"

In short: the answer is "well, you're hosed." But GPG has some other features built-in to help you out. You just need to be prepared. That usually means having a revocation certificate ready to use. I'll cover that in a moment.

If you have lost your secret key (the secret keyring file itself) for any reason, for all intents and purposes you cannot ever decrypt anything that was encrypted with your public key ever again. The secret key is almost assuredly much, much more complex than the password or passphrase that you chose to protect it. As MC Frontalot would say: "you can't hide secrets from the future with math." so when petaflop computing power comes to the desktop, you may be able to crack it in a matter of months. Until then, your data is gone. This includes any new communication sent to you from others who have your public key.

Obviously, if people are sending you encrypted data and you have no way to decrypt it, that's A Bad Thing™.

If you have simply forgotten your passphrase, and it's a simple one that's 8 characters or less, alpha-numeric with upper/lowercase and no keyboard symbols, you may be able to brute-force the password that is protecting the key. That's way beyond the scope of this post.

Enter: Key Revocation
Revoking your public key is a quick way to advertise that the key should no longer be used. This can be for many reasons. The most obvious is if you feel your secret key has been compromised. In the event that your workstation got rootkitted, your backups were stolen, or you errenously left your secret key somewhere that it could have been accessed by someone else, you can't rely on the passphrase itself to maintain absolute secrecy of your data. Remember: passphrases can be cracked much easier than the unprotected secret key itself.

When to generate a revocation certificate:
I usually generate one soon after generating my keypair, which states "I have lost the secret key" or something of that nature. If you lose the secret key or forget the password to it, it's too late to generate the revocation certificate. You need both the secret key (and thus its password) to do this.

If you fear that the key has been compromised, you should generate one at that time which states the nature of the compromise.

To generate a revocation certificate, issue "gpg --gen-revoke [keyID]" and follow the prompts.

$ gpg --gen-revoke 19A473C7

sec  1024D/19A473C7 2009-04-25 Test! (This one is getting revoked!) 

Create a revocation certificate for this key? (y/N) y
Please select the reason for the revocation:
 0 = No reason specified
 1 = Key has been compromised
 2 = Key is superseded
 3 = Key is no longer used
 Q = Cancel
(Probably you want to select 1 here)
Your decision? 3
Enter an optional description; end it with an empty line:
> I'm revoking this on purpose
>
Reason for revocation: Key is no longer used
I'm revoking this on purpose
Is this okay? (y/N) y

You need a passphrase to unlock the secret key for
user: "Test! (This one is getting revoked!) "
1024-bit DSA key, ID 19A473C7, created 2009-04-25

ASCII armored output forced.
Revocation certificate created.

Please move it to a medium which you can hide away; if Mallory gets
access to this certificate he can use it to make your key unusable.
It is smart to print this certificate and store it away, just in case
your media become unreadable.  But have some caution:  The print system of
your machine might store the data and make it available to others!
-----BEGIN PGP PUBLIC KEY BLOCK-----
Version: GnuPG v1.4.9 (OpenBSD)
Comment: A revocation certificate should follow

iGUEIBECACUFAknzlDweHQNJJ20gcmV2b2tpbmcgdGhpcyBvbiBwdXJwb3NlAAoJ
EPfQr48ZpHPHbu8AoKRL0GJFb4MfgeaNYcjh9NUrMPQcAJ92z9KS9yA7TvNVZe2M
eMyWmaULZQ==
=NzxY
-----END PGP PUBLIC KEY BLOCK-----

This key, if it falls into the wrong hands, can be used by anyone to revoke your public key! Make sure to keep it safe. Back it up onto long-term storage that is reliable, or even print it out. It's relatively short, so it won't be too hard to type it in manually.

To use the revocation cert, simply import your public key (if it's not already in your keychain) and import the revocation cert. This will merge it with your public key and notify GPG that it's no longer valid. Then, if you have exported your public key to a keyserver, export it again as shown in part 1.

$ gpg --import testrev.txt 
gpg: key 19A473C7: "Test! (This one is getting revoked!) " revocation certificate imported
gpg: Total number processed: 1
gpg:    new key revocations: 1
gpg: 3 marginal(s) needed, 1 complete(s) needed, PGP trust model
gpg: depth: 0  valid:   2  signed:   0  trust: 0-, 0q, 0n, 0m, 0f, 2u

You should also contact those who may send you communication and let them know to refresh your key from the keyserver. Until they do so, their installation of GPG (or other OpenPGP compliant software) will not know your public key has been revoked.

Of course, it's best to avoid the need to revoke certificates in the first place!

• Keep your secret key in a safe place, such as on your workstation, not a file-server or a shared host.
• Keep UNIX permissions at 600 (rw- --- ---) or otherwise make sure your account is the only one that can access the keyrings and/or any exported secret keys.
• Back up your keys to long-term media (CD-RW is usually fine) and keep it in a place that's safe from attackers and environmental harm (a cool, dark, dry place like a fire safe).
  
• For crying out loud, remember your passphrases without making them short and/or easy to guess. Example: use a favorite quote or passage written in l33t. Preferably a passage that few people know you like. Using your email signature line? Bad idea.

GPG Part 1: Key Management, Key Signing

Introduction
Although I'm a fan of TrueCrypt for full-disk encryption and folder encryption I still rely on Gnu Privacy Guard for some of my needs. GnuPG is an Open-Source encryption tool that adheres to the OpenPGP standard. That means that this should also work on most other CLI OpenPGP-compatible packages as well. It's lightweight, cross-platform, and there are front ends that make it relatively easy to use. It can output ASCII that's easy to send in an e-mail or copy/paste into a document.

Compiling and installing GnuPG is beyond the scope of this article. That said, it's usually easy to install without compiling it, since GnuPG is available in many package repositories for Linux, BSD and OS X. Try installing gnupg, gpg or GnuPG to see if it shows up in the repository. On OpenBSD, it's as simple as running "sudo pkg_add -r gnupg". The windows package is available through the GnuPG website (linked above).

Today, I'm going to focus only on the command-line key-management features. They work the same on all platforms.

Quick-Ref
Look, I know some of you guys probably don't need to see the whole screen-shot walk-through for this. If you just want to tinker around or you already have some experience with PGP-Like tools and just want to know how to use a keyserver, sign other peoples' keys and the like, here are a few helpful commands.

Generate a new key:       gpg --gen-key
Show secret keyring:      gpg --list-secret-keys
Show public keyring:      gpg --list-keys
Export a public key:      gpg --export -a --output [filename] [hex KeyID]
Export a secret key:      gpg --export-secret-keys -a --output [filename] [hex KeyID]
Get key from keyserver:   gpg --keyserver [server] --recv-keys [hex KeyID]
Send a key to keyserver:  gpg --keyserver [server] --send-keys [hex KeyID]
Inport a key from file:   gpg --import [filename]
Sign a key:               gpg --sign-key [hex KeyID]
Editing keys (advanced):  gpg --edit-key [hex KeyID]

Generating your first key
If you've never used GnuPG before, you will have to generate a key pair. This key pair includes a public key and a secret key. The public key can be shared, and is used by anyone who wishes to send you something encrypted. Using your password-protected secret key, you can decrypt what is sent to you. This is called asymmetric crypto because a different key is used for encryption and decryption.

To generate a new key pair, use gpg --gen-key and then follow the prompts.

-bash-3.2$ gpg --gen-key
gpg (GnuPG) 1.4.9; Copyright (C) 2008 Free Software Foundation, Inc.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

gpg: directory `/home/axon/.gnupg' created
gpg: new configuration file `/home/axon/.gnupg/gpg.conf' created
gpg: WARNING: options in `/home/axon/.gnupg/gpg.conf' are not yet
active during this run
gpg: keyring `/home/axon/.gnupg/secring.gpg' created
gpg: keyring `/home/axon/.gnupg/pubring.gpg' created
Please select what kind of key you want:
   (1) DSA and Elgamal (default)
   (2) DSA (sign only)
   (5) RSA (sign only)
Your selection? 0
DSA keypair will have 1024 bits.
ELG-E keys may be between 1024 and 4096 bits long.
What keysize do you want? (2048) 2048
Requested keysize is 2048 bits
Please specify how long the key should be valid.
         0 = key does not expire
        = key expires in n days
      w = key expires in n weeks
      m = key expires in n months
      y = key expires in n years
Key is valid for? (0) 0
Key does not expire at all
Is this correct? (y/N) y

You need a user ID to identify your key; the software constructs the user ID
from the Real Name, Comment and Email Address in this form:
    "Heinrich Heine (Der Dichter) <heinrichh@duesseldorf.de>"

Real name: HiR Team
Email address: team@h-i-r.net
Comment: HiR Information Report - http://www.h-i-r.net 
You selected this USER-ID:
    "HiR Team (HiR Information Report - http://www.h-i-r.net) 
    <team@h-i-r.net>"

Change (N)ame, (C)omment, (E)mail or (O)kay/(Q)uit? O
You need a Passphrase to protect your secret key.
... Password Mumbo Jumbo ...

We need to generate a lot of random bytes. It is a good idea to perform
some other action (type on the keyboard, move the mouse, utilize the
disks) during the prime generation; this gives the random number
generator a better chance to gain enough entropy.
+++++.+++++.++++++++++++++++++++++++++++++.++++++++++.++++++++++++++++++
++++++++++++.++++++++++..++++++++++++++++++++++++++++++..++++++++++++++
++++++>....+++++.......+++++....+++++.....+++++....+++++
We need to generate a lot of random bytes. It is a good idea to perform
some other action (type on the keyboard, move the mouse, utilize the
disks) during the prime generation; this gives the random number
generator a better chance to gain enough entropy.
++++++++++.++++++++++++++++++++.++++++++++++++++++++++++++++++++++++++++
+++++++++++++++++++++++++..++++++++++.......+++++..+++++++++++++++.+++++
.+++++.++++++++++++++++++++.+++++.+++++...........+++++...........+
+++++++++..+++++.................................+++++...............
........................................................................
..........+++++^^^
gpg: /home/axon/.gnupg/trustdb.gpg: trustdb created
gpg: key 1ACB0D01 marked as ultimately trusted
public and secret key created and signed.

gpg: checking the trustdb
gpg: 3 marginal(s) needed, 1 complete(s) needed, PGP trust model
gpg: depth: 0  valid:   1  signed:   0  trust: 0-, 0q, 0n, 0m, 0f, 1u
pub   1024D/1ACB0D01 2009-03-12
      Key fingerprint = 86B3 38F5 7999 73C9 F4D3  CA65 90FC CDF3 1ACB 0D01
uid                  HiR Team (HiR Information Report - http://www.h-i-r.net)
         <team@h-i-r.net>
sub   2048g/5D6C5DEE 2009-03-12

The end result is a secret key and a public key which you can view with the --list-secret-keys and --list-keys options.

Showing your keyrings

As mentioned above, the commands for listing the contents of your keyrings is simple. You can also see that my personal key (ax0n@h-i-r.net) is already in my secret and public keyring.

-bash-3.2$ gpg --list-secret-keys
/home/axon/.gnupg/secring.gpg
-----------------------------
sec   1024D/1ACB0D01 2009-03-12
uid                  HiR Team (HiR Information Report - http://www.h-i-r.net)
 <team@h-i-r.net>
ssb   2048g/5D6C5DEE 2009-03-12

sec   1024D/7144C09F 2008-02-02
uid                  ax0n@h-i-r.net <ax0n@h-i-r.net>ssb   2048g/1622B636 2008-02-02

-bash-3.2$ gpg --list-keys
/home/axon/.gnupg/pubring.gpg
-----------------------------
pub   1024D/1ACB0D01 2009-03-12
uid                  HiR Team (HiR Information Report - http://www.h-i-r.net)
 <team@h-i-r.net>
sub   2048g/5D6C5DEE 2009-03-12

pub   1024D/7144C09F 2008-02-02
uid                  ax0n@h-i-r.net <ax0n@h-i-r.net>sub   2048g/1622B636 2008-02-02

Exporting your keys

You can export your key to an ascii file with the following command. Note, we use the hex key ID for our public key as shown above. By default, GPG exports in a binary format. the "-a" option enables "ASCII Armor" mode, which is similar to uuencode or base64 in that it takes up more characters but is more human-readable.

-bash-3.2$ gpg --export -a --output team.key 1ACB0D01
... we might as well look at the results, right? 
-bash-3.2$ cat team.key
-----BEGIN PGP PUBLIC KEY BLOCK-----
Version: GnuPG v1.4.9 (OpenBSD)
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BEnocAgRBADZ3ju47qDUqTRMY7wIr81aOqaXxfTw7/JdgKAV29szXkj1Hc8k+nfe
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CWHHR8iC57860/PQkgqpwUzeqVDy5ELd4mbRaUdPLhVlijn25zEiao/LDaHI1TQx
A/4q5aK3YAS0J74K5a2P/73NnEHsYMPCusrj3PRKejDhg9HwS70RgHh1s414hcSm
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DQe7QyD3cyuM5T//6IQsS67wteqyBjU2Yi4p725YHfQZ8rRDSGlSIFRlYW0gKEdl
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HgECF4AACgkQCxvsb9wupskDMgCeKHz04FiTfVJI2Gul3bZ1M/YM/nAAn2mjsDGH
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nY0yda2QeQ0V9QiUeqp8L+CVCTYObo3OnS+Y6OJrs8M3IeAhV3Jr5DHt1U6J4BEk
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1VIAniKKY6smdU2WBDq0+EeQE25xF2ld
=Lt53
-----END PGP PUBLIC KEY BLOCK-----

You can upload the public key to your website and link to it. You can attach it in email, or you can just copy-and-paste it since it's ASCII Armored.

Using the --export-secret-keys option, you can similarly export your secret key. Make sure to use the -a option if you wish to have it in a text file format. AND BE SURE TO KEEP THIS KEY SAFE. If your secret key is compromised, the password protecting it is a relatively small obstacle compared to the key itself.

You can also export your public key to a keyserver. This is a public repository that lets people search for and request GPG keys for people they know. Many of these keyservers are synchronized with one another. Read about Synchronizing Key Servers here. Two SKS search links:

keys.keysigning.org

keys.nayr.net

I'll use keys.keysigning.org in this example, since it's an SKS. To send your key to the keyserver, use the keyserver name and the hex KeyID from gpg --list-keys:

-bash-3.2$ gpg --keyserver keys.keysigning.org --send-keys 1ACB0D01
gpg: sending key 1ACB0D01 to hkp server keys.keysigning.org

Things to keep in mind when you upload to a keyserver:

• You can upload anyone's public key to a keyserver, but you probably shouldn't without their permission. The exception is if you're going to sign someone else's key that's already on a keyserver. I'll cover that later.
• The email addresses, names, and any other information that's part of the key will be forever stored in plain-text and indexed. This could open the email address up to being spammed, or could reveal more personal information than you'd liked. I'm just saying be careful with what you put in your key. The metadata may become public.

Importing keys

You can import keys a few different ways. The most basic is to download the key or paste and save the key as a text or ascii file. Then you import the key with --import [filename]

You can import both public and secret keys this way. GPG will auto-detect what kind of key you import.

-bash-3.2$ gpg --import phoneboy.gpg
gpg: key 597F5D2A: public key "Dameon D. Welch-Abernathy " imported
gpg: Total number processed: 1
gpg:               imported: 1
gpg: 3 marginal(s) needed, 1 complete(s) needed, classic trust model
gpg: depth: 0  valid:   4  signed:   0  trust: 0-, 0q, 0n, 0m, 0f, 4u

Hopefully, Phoneboy does not mind me using his key as an example. He links to it from his blog (which is a good read if you're into telecom and/or security stuff)

You can also import the key from a keyserver, much like the export we described above. You do need to actually go to the keyserver to find the Hex KeyID though, or A856F98C in this example, which is Packet Storm Security's key.

-bash-3.2$ gpg --keyserver keys.nayr.net --recv-keys A856F98C
gpg: requesting key A856F98C from hkp server keys.nayr.net
gpg: key A856F98C: public key "Packet Storm Security " imported
gpg: 3 marginal(s) needed, 1 complete(s) needed, classic trust model
gpg: depth: 0  valid:   4  signed:   0  trust: 0-, 0q, 0n, 0m, 0f, 4u
gpg: Total number processed: 1
gpg:               imported: 1

The Web Of Trust

The beautiful thing about GnuPG (and other PGP-based solutions) is that you can create a "web of trust" with friends and colleagues using a keyserver. Basically, you have other GnuPG users you know sign your key. This means that they have certified that a public key belongs to you. With enough signatures on your public key, this makes it more difficult for an impostor to masquerade as you. The GNU Privacy Handbook's section on Building Your Web Of Trust explains it in more detail.

In the examples I've shown importing keys, you can see some information about depth, trust, signed, and the like. I won't get too deep into this, just enough to get you started because the above link really is a good read.

If someone sends you a public key, you can't 100% trust that it is theirs, especially if it's someone you do not know well or in person. It may belong to an imposter who has registered a convincing email address and has created their own key. Communication that you encrypt for the person you believe you're talking to could actually fall into unintended hands. It is for this reason that key signatures come in handy.

Fingerprints are cryptographic hashes that can be used to authenticate the key, but are short enough that one can scrawl them onto a napkin or the back of a business card. If you have verified the fingerprint of a person's key while you're there in person, you can verify that fingerprint against the key when you receive the key from them (or from a key server) later on. Once you verify that the key is authentic, you can "sign" it and then re-upload it to the keyserver. This means that you have personally vouched for the key's authenticity. If enough people vouch for one another's keys, the Web Of Trust is formed. Any person who may not know someone well enough to trust the key can see that several people vouch for the authenticity of the key. Perhaps one of the signers is even a mutual friend.

Key Signing
Signing is pretty easy:

You import a key from a keyserver (see example above)

You sign the key: gpg --sign-key [KeyID] (you'll be prompted for your passphrase)

You export the key back to the keyserver (see example above)

Key-Signing Parties
Throwing a Key-Signing party is a geeky way to vastly increase the size of your Web Of Trust and maybe interest others in encryption.

If you're going to try to get some people together to sign one another's keys (say, your local hackerspace, the 2600 participants, or your colleagues in the office), you should have a few things in place:

1. Every participant's public key should be uploaded to an agreed-upon keyserver or synchronizing keyserver network.
2. Every participant should have their hex KeyID, Name/Email and public key fingerprint written down or printed out. It's easier if participants print out several copies per page of paper (as shown in the photo) and cut them into strips to hand out to other participants.
3. All the participants should know one another and be able to verify each other's identity. You don't need to flash Drivers' Licenses and compare them to the real name on the key, but it wouldn't hurt.

My Keysigning Party Paper just repeats the following block of text as produced by gpg --fingerprint [keyID]:

pub   rsa3072 2021-07-18 [SC] [expires: 2031-07-16]
      29A2 4961 E62E DC91 AC9B  5FED 6421 2F30 5A35 5321
uid           [ultimate] Noah Axon (Main GMail) <focushacks@gmail.com>
uid           [ultimate] ax0n@h-i-r.net <ax0n@h-i-r.net>
sub   rsa3072 2021-07-18 [E] [expires: 2031-07-16]

Participants basically make their rounds, gathering key information from every other person in the group. Then, everyone imports everyone else's key from the keyserver and verifies that the fingerprints and e-mail addresses match the ones they were given in person. After that, sign all the keys, and export the keys back to the keyserver.

Yes, this is a manually intensive process.

 

Continue: GPG Part 2: Key Revocation

Rubber-hose cryptanalysis and how to not get a wrench to the head

From xkcd this morning:


In the security industry, we call this "rubber-hose cryptanalysis" -- a euphemism coined by Marcus Ranum for getting the target to give you access to the encrypted data via coercion. The name implies physical torture, but psychological coercion (threatening physical harm, litigation, etc) is pretty much the same thing. I personally consider this a variety of Social Engineering since it relies on manipulating your mark rather than using technology to directly attack the assets.

When attacking many modern cryptosystems, a technological attack is often going to take a lot longer than simply bludgeoning it out of someone. Some technological attacks that don't directly involve breaking the crypto through brute force can sometimes get decrypted data :

• Dumping the contents of the target's RAM and Swap file (can contain the crypto key, unencrypted data, evidence of encrypted data or metadata about the encrypted files)
• Operating system history "recently used" (can store history data and reveal structure of the encrypted volume)
  

When legally possible, you should never, ever relinquish your encrypted data. When faced with torture and/or the loss of your freedom, you still have a friend in your corner: deniable encryption.

Simply put, deniable encryption most often refers to encrypted data which can resolve to both the genuine data and decoy data, depending on the key used to decrypt the data. The decoy data should appear to be "secret" in nature, and it's best if the decoy data appears to be the same kind of data that you're really trying to protect. If you encrypted a bunch of proprietary documentation, your attacker may know what they're looking for. You'd be best to make the decoy data look like proprietary documentation while remaining innocuous, perhaps loaded with misleading facts. Using a video of Rick Astley's Never Gonna Give You Up might tip the attacker off that they need to keep looking (and torturing you) for the real goods.

While not the only tool available, one commodity piece of free, cross-platform software that handles this task quite nicely is TrueCrypt. It handles full-disk encryption, deniable encryption (which is called a "hidden volume" in TrueCrypt), and can even boot an operating system from a hidden volume. That's right, TrueCrypt can boot an entirely different operating environment based on which pre-boot passphrase you enter.

I'll save the merits and woes of full-disk encryption for another day.

The dangers of proliferation of shared FTP accounts

In a medium sized education organization which shall remain anonymous; FTP and windows file sharing is the file transport of choice for distributing small reports and data chunks. For a long time when a ftp account was needed the person would simply call up the first person who maintained a server that came to mind and had one created. The new ftp account was then fed into a script on the database server (mainframe or AS/400) which then once a day/month/year it spit out a report and uploaded it to the server where (someone/something/every one) picked it up and either loaded it into a different script, or dumped it into a spread sheet, did their business then deleted it and went to lunch.

This has gone on for decades with out some one pointing out that there is something wrong with this process.

Let me count the ways this is wrong:
1. It's not encrypted.
Packet sniffers are very easy to implement even on a switched LAN.
2. There is no way to prove that the remote host is what it says it is.
Server spoofing via DNS or Denial of Service.
3. Access control (in this case) isn't managed.
Static user names and passwords being passed in the clear.
4. Proliferation of potentially sensitive data
Just about every industry is required by law to protect certain kinds of data.
5. Use of old and un-maintainable server for warehousing information.
No warranty, use of old 3rd party software which is unmaintained, End-of-life OS.
It's potential for being 0wned is pretty high.
6. Total disregard of Intranet and Internet facing status of server.

Why? You ask has this issue been allowed to even occur?

Reason #1 Impending retirement. Why would some one who is retiring in 5 or so years would want to learn something new? Ftp and windows file sharing is well known. Ftp has been used on open systems since their inception so everybody supports it. (I mean the standard supports 7 bit file transfers, from the time when bits were expensive, really when is the last time you NEEDED to transfer something using 7 bits as opposed to 8bits?).

Reason #2 Bypassing the chain of command. Why follow protocol and make an official request when you can call the person maintaining the server and have them do it for you.

Reason #3 Maintainers versus dedicated IT staff. In most small and medium organizations, they cant afford dedicated IT staff so they give the position to some one who already does something else. The problem is that the person just puts out fires and performs maintenance. They don't keep up on industry issues and so long as the server limps along everything is fine.

Conclusion:
Because the chain of command is bypassed the Network Administrator isn't aware of it. And the only way he or she will find out about it is either an audit, if it fails or if the server is totally Pwned and now is now selling generic Viagra. Should the latter be the case, a pile of finger pointing ensues and you can guess the rest.

Alternatives:

The solution is finding a suitable replacement technology which is secure and possesses controls on access and availability yet is similar to an existing process so you take advantage of the users existing habits instead of putting them into an uncomfortable situation of learning some "NEW" computer process.

1. Pre configuring the email client to use encryption. Email is one of those skills that every one knows or should know.
   
2. Implement Ftp over SSL on a managed file server .(Windows, Linux, Novell ...etc) Most of them have some form of secure drive mapping or mounting which is done transparently to the user. This really is the best choice because most modern server platforms possess some form of auditing features which allow you to track access to resources and or files.
   
3. Secure web application for reports and data. Automate the process and load it into a database then generate the reports on a web page or make it available as a download. A well designed web system can contain all of the controls to keep data safe. Surfing the web is a national pastime, provided you make a usable web interface.

Perhaps in conjunction with...

1. Controlling movement of data. Prevention of use of external storage devices.
   
2. Encrypting file contents using authentication. Smart cards, public/private keys, hardware keys...etc

Information security is not about being perfectly secure, it's about maintaining a good balance of security vs. usability.

Sysadmin Sunday: Encrypted Swap Space in FreeBSD

New research shows that cold boot attacks can compromise encryption by giving you access to the RAM's contents. This even applies to full-disk encryption that encrypts swap space and whatnot. We'll probably talk more about that in our podcast.

Physical access almost always means that a total compromise of security is somehow possible. Sensitive data could be at risk long after the data in RAM decays into oblivion. Encryption keys, large documents, and other files containing data you don't want falling into the wrong hands will almost certainly see their fair share of time in virtual memory. That means pages of RAM will be written, for better or worse, to the hard drive.

Encrypting just your swap space can be easier than switching to full-disk encryption and makes it more difficult for an attacker to obtain sensitive data as it gets shuffled in and out of RAM.

OpenBSD encrypts swap by default without any further action. To the best of my knowledge it's alone in that fact. I can't outline how to encrypt swap space in every operating system, but since FreeBSD's the flavor-du-jour, I'll show you how easy it can be.

First, disable swap:

[axon@floaty-fbsd ~]$ sudo swapoff -a
swapoff: /dev/ad0s1b: Cannot allocate memory

Whoops! If there's too much stuff running to fit in RAM without swap, you'll need to cut back. Close your applications, stop the X Window system or whatever you have to do. Let's try that again.

[axon@floaty-fbsd ~]$ sudo swapoff -a

Now, find the swap partition and over-write it using dd(1) to stream /dev/urandom to it. It could take a while depending on the size of the swap partition. Yes, this is a paranoia countermeasure and nothing more. Keep in mind that only freshly-used parts of swap will be encrypted once we're finished. Right now, there could be (ab)usable data out there. Not for long!

[axon@floaty-fbsd ~]$ grep swap /etc/fstab
/dev/ad0s1b none swap sw 0 0
[axon@floaty-fbsd ~]$ sudo dd if=/dev/urandom of=/dev/ad0s1b
dd: /dev/ad0s1b: end of device
464657+0 records in
464656+0 records out
237903872 bytes transferred in 88.835558 secs (2678025 bytes/sec)

To enable GEOM ELI on your swap partition, edit /etc/fstab and add ".eli" to the end of the swap device.

[axon@floaty-fbsd ~]$ sudo vi /etc/fstab
change this line:
/dev/ad0s1b none swap sw 0 0
to this:
/dev/ad0s1b.eli none swap sw 0 0

You have to reboot for this to take effect. Once it comes back online, use kldstat and swapinfo to verify that the geom_eli.ko module is loaded and that the new swap device is being used.

[axon@floaty-fbsd ~]$ kldstat
Id Refs Address Size Name
1 10 0xc0400000 7b2d2c kernel
2 1 0xc0bb3000 6974 snd_ich.ko
3 2 0xc0bba000 239a8 sound.ko
4 1 0xc0bde000 5c304 acpi.ko
5 1 0xc1f19000 e000 geom_eli.ko
6 1 0xc1f27000 19000 crypto.ko
7 1 0xc1f40000 a000 zlib.ko
8 1 0xc21ec000 2000 warp_saver.ko
[axon@floaty-fbsd ~]$ swapinfo
Device 1K-blocks Used Avail Capacity
/dev/ad0s1b.eli 232328 0 232328 0%

Voila!

Sysadmin Sunday: Quick & Dirty SSH Tunneling

Occasionally, you might need to tunnel some other traffic over SSH. This could be to get access to an external web proxy, to get a remote X display up, or to get around a firewall-blocked port that you must access.

The syntax (on the command-line OpenSSH client) for a Local forward is like this:

# ssh remote-example.h-i-r.net -L 3128:localhost:3128

This tells my SSH client to tunnel traffic to port 3128 on my workstation to port 3128 on my DMZ box. Port 3128 isn't accessible because of a firewall, but tunnelled over SSH it works fine. In this case, I'm running squid on the remote example host. Telling Firefox to use http://localhost:3128 as the proxy will now tunnel all of my web traffic over the SSH tunnel to the squid proxy behind the firewall. The reason it's called a local forward because it forwards a local port over the SSH connection.

A remote forward will open up a port on the remote machine and connect it to a port on the client's network. The syntax is similar:

# ssh remote-example.h-i-r.net -R 3306:dbserver:3306

This would open up port 3306 (the MySQL server port) on the remote host and tunnel it to the MySQL service on the host named dbserver on my local network.

While running forwarding of either type, you can enter the hotkey sequence "~#" to see all the open connections through the forwarded ports.

TrueCrypt 5.0 Released

TrueCrypt 5.0 , a Free, Open-Source On-the-fly encryption tool came out this week.

Highlights from the release notes:

• Mac OS X Support (Tiger and Leopard on both Intel and PPC architectures)
• Windows performance enhancements
• Pre-boot authentication and system drive encryption for Windows
• Enhancements to the Linux version

This tool is fast becoming a favorite among security professionals, privacy advocates and the paranoid.

Stegnagraphy overview

-Stegnagraphy Introduction-

I think we’re all guilty of drawing up the plans in our heads, with the thermite charge on your hard drive and the big red panic button. But all of these plans essentially have the problem of having to detect a breach of security. An interested party need only be just as creative to detect and thwart your carefully laid booby trap. Nothing quite says "I contain incriminating information" like a booby-trapped PC.

There are some classical methods of hiding communication in plain sight using pre-arranged coded speech an writing patterns which at first look appear as mundane however in actuality the people as saying something completely different. The Russian black market and crime syndicates developed a language using certain chess movements. Prison detainees used vulcanized rubber and crude utensils to draw elaborate tattoo’s denoting rank and other qualities.

By itself stegnagraphy is only good for covert communications to one or more parties. Much has been said about the presence of stegnagraphy laced content in news groups and other public content. Granted the amount of actual covert communications is very exaggerated. The difficulty in using stegnagraphy is that many stegnagraphy techniques can be scanned for just like you would scan for a virus or malware. The very presence of a stegnagraphic utility on your computer or some one accessing a known security website or downloading a known utility can raise a flag to a security analyst that covert communication is likely occurring.

When addressing the topic of including stegnagraphy into freenet (an open source anonymous network) "...Steganography is an ongoing battle of attrition, obscurity and constantly updating are sadly the best defenses in it. Again it's down to `better
the way we do it than the way you don't...' " Basically, the same defenses that viruses use to avoid detection are the only strengths that stegnagraphy by itself has. Another strength it has is that it is not part of the popular user-land security dogma which states that firewall + anti virus + anti spy ware == secure. (which is like saying that its okay not to wear a seat belt in a car because your wearing a condom). So it is only effective against passive detection but thats about it.

-=- TABLE OF CONTENTS -=-
x .......... Introduction
1 .......... Use and purpose
2 .......... Mediums and How it works
3 .......... Utilities currently available
A .......... Works Cited

=======================
1 .......... Use and purpose
=======================
Covert communication is where bandwidth is stolen from a legitimate communication to create a secret channel of communication. So the purpose of stegnagraphy is to create a parasitic hidden communication, carried by a legitimate communication. This is done so that communication can be made in a public space with out drawing attention to it self.

A person who would want to make use of this would be a human rights violation observer who is passing information to an international human rights advocacy group like Amnesty International or the UN. The local authorities would very likely be suppressing information of that sort. If the local authorities would catch a communication a report on an incident, its very likely the reporter would be silenced in one way or another.

(rant)
In the US we enjoy freedom of speech, these rights are being whittled away at under the guise of national security. In other countries, un-censored speech has dire and deadly consequences. Just because what I write may be unpopular, that is not a valid excuse for killing or torturing me. Yet untold numbers of people suffer those consequences daily just because they say something not deemed acceptable by their locality/nation/culture. Development of covert communications and cryptography may seem trivial to us now, but development of these tools can save lives. Allowing the public the use of these tools may have serious consequences for law enforcement, but criminalizing their use and possession has vast and horrible consequences for us as society.
(/rant)
=======================
2 .......... Mediums and How it works
=======================

A good example is a chess game, in the previous example of criminal elements use of coded speech and mannerisms, a chess game is interpreted in a different game, certain reactions to moves are communications, the moves are all valid moves, only their context has changed. This is a high bandwidth covert channel, it uses a lot of the bandwidth of the communication. High bandwidth is where the legitimate communication itself is placed into a different context and interpreted to mean something else. If one of the players affixed a microdot containing private information and affixed it on to the other players chess board then this would be low bandwidth.

The Trusted Computer Security Evaluation Criteria (aka TCSEC) is a set of criteria established by the National Computer Security Center which is managed by the NSA. According to TCSEC there are two types of covert communications. The first is a storage channel, which modifies a stored object into something else less sensitive. The second is a timing channel which manipulates the timing in a communication to transmit the sensitive information.

An example of the two is Jsteg and tcp/ip timing. Jsteg hides information in an existing jpeg in the formatting of the picture which does not significantly change the original picture. Tcp/IP timing is where a normal mundane tcpip request is carried out but it is delayed in a pre-determined fashion which the timing of the transmition of the packets is the medium of communication. A less technical example would be the chess example where the microdot would be the storage channel and the timing of chess movements would be the timing channel.

Another example of using a parasitic medium is communicating using stegnagraphy using what is called chaffing and winnowing. This sends out multiple hidden communications using a secondary channel to provide a key to identify which communication is correct. This method utilizes the previous forms and adds in a code which authenticates the communication.

Lastly, the weakness of stegnagraphy is that it relies on constant change to maintain the communications secrecy. Companies like SARC are using watermarking technologies which are similar to anti-virus technologies to detect both stegnagraphic content and utilities, it is vital that cryptography be used in order to maintain the secrecy of the information within the hidden communication.

=======================
3 .......... Utilities currently available
=======================
From Wikipedia (http://en.wikipedia.org/wiki/Steganography#Implementations)

Online (Hiding text)

* mozaiq Has a large library of stock photos it provides if you can't supply a photo of your own. A good starting point for creating simple steganographic examples.
* spammimic.com will take a sentence that you provide and turn it into text that looks to all the world like spam.
* Hide text in a PNG or BMP image and its corresponding decoder.

** Online (Hiding files)

* Stegger, PHP Steganography—PHPClasses Repository—An open source, feature rich, secure implementation of image steganography written in PHP.

** Downloadable (Hiding text)

* Concealar ...coz a picture speaks a thousand words! The software "Concealar" hides text into images & pictures by a password using cryptographic and steganographic techniques. Encryption algorithm used for text is AES (Rijndael) and the password is hashed with SHA512. The software don't create any noise in the resultant image so pattern-finding & pixel-mapping techniques of steganalysis don't work on this software.
* Bapuli Online—implementing steganography using Visual Basic.
* BitCrypt BitCrypt is one of the easiest to use encryption tools which at the same time provide ultra-strong encryption. It uses up to 8192 long bit key ciphers to encrypt the text, and then stores the encrypted text within bitmap images.

** Downloadable (Hiding files)

* Hiding Glyph: Bytewise Image Steganography: Hides any file (or folder) into any losslessly compressed image (BMP, PNG, etc…). (freeware)
* BestCrypt Commercial Windows/Linux disk encryption software that supports hiding one encrypted volume inside another
* Crypto-Stego Utility for the Zillions of Games program.
* Digital Invisible Ink Toolkit An open-source cross-platform image steganography suite that includes both steganography and steganalysis implementations.
* FreeOTFE Free, open-source Windows/PocketPC/Linux disk encryption software that supports hiding one encrypted volume inside another, without leaving any evidence that the second encrypted volume exists. This probably resists any statistical analysis (as opposed to tools that conceal data within images or sound files, which is relatively easy to detect).
* MP3 Steganographic File System, a description of an approach to create a file system which is implemeted over MP3 files.
* OutGuess A steganography application to find data in Jpeg images.
* PCopy A steganography commandline tool with a userfriendly wizard which can produce lossless images like PNG and BMP. Special features are RLE, Huffman compression, strong XOR encryption and the Hive archiving format which enables the injection of entire directories.
* Phonebook FS protects your disks with Deniable Encryption
* RevelationA platform independent tool created in Java that can hide any data file within a 24-bit bitmap image. Features a unique wizard style interface in the encoding and decoding process.
* stego and winstego Steganography by justified plain text.
* Stego-0.5, a GNOME/GTK+ based GUI for LSB algorithm. License (GPL)
* Stego Archive Source for a large variety of steganography software.
* Steghide Free .jpeg and .wav encryption for Linux and other operating systems.
* SteGUI Free GUI for Steghide for Linux.
* TrueCrypt Free, open-source Windows/Linux disk encryption software that supports hiding one encrypted volume inside another, without leaving any evidence that the second encrypted volume exists. This probably resists any statistical analysis (as opposed to tools that conceal data within images or sound files, which is relatively easy to detect).
* Peter Wayner's website—sample implementations of steganographic techniques, by the author of Disappearing Cryptography.
* NetTools Steganography by hiding data in pictures, archives, sounds, text files, html, and lists.
* Qtech Hide & View v.01 is the newest BPCS-Steganography program for Windows. This is an image steganography. (Free to use)
* ZebDisk ZebDisk is a free software, and you can store, and share your files on the internet with it using Google’s Picasa service.
* SteganoG a simple program to hide a text file in a .bmp file.
(Wikipedia, on Implemenataions of Stegnagraphy, Dec 2007)

We also mentioned Jsteg which can be found at "http://www.theargon.com/achilles/steganography/jpeg-steg/"

=======================
A. .......... Works cited
=======================
Sarc Website. Accessed March 2007
http://www.sarc-wv.com/default.aspxn-

Toad "Attacks and weaknesses." Accessed March 2007
http://www.freenethelp.org/html/AttacksAndWeaknesses.html

Engle, Sophie. (Viewed March 2007). "CURRENT STATE OF STEGANOGRAPHY:
USES, LIMITS, & IMPLICATIONS"
http://wwwcsif.cs.ucdavis.edu/~engle/stego.pdf

Wikipedia.org (Accessed March 2007). "Steganography"
http://en.wikipedia.org/wiki/Steganography

Wikipedia.org (Accessed March 2007). "Covert Channel"
http://en.wikipedia.org/wiki/Covert_channel

Wikipedia.com (Accessed March 2007). "Russian Criminal Tatoos."
http://en.wikipedia.org/wiki/Criminal_tattoo#Russian

http://www.theargon.com/ (Accessed December 2007). "theargon stegnagraphy web archives."
http://www.theargon.com/achilles/steganography/jpeg-steg/

MS EFS and Vista security *features*

Everybody and their brother have commented on the chatty-ness on MS Vista. My one note on this is that the administrative dialog that appears whenever any one accesses an item that requires administrative privileges is that the solution is a dialog level. This is similar to debians DPKG prompt level setting which sets the dialogs between only serious messages (something which has the capacity to brick the computer if not answered) to trivial (Everything, no matter how trivial.)

Microsoft’s choice to do this method of alerting users is pointless clutter. It trains the user to press "OK" on everything, which is a terrible idea that is the root cause behavior to the MS in security problem. This behavior is caused by how they are handling authentication tokens. A second token is created carrying administrative privileges and adds to the users current authentication token for the purpose of using administrative functions.

We all some times say something like "... "What they ought to have done is ..." I remember saying it a lot in middle and high school, hence my concern about saying it too often. But creating a utility witch catalogs all apps, control panels requiring admin privileges which limits its access to the rest of the system. Take for instance an old version of a children’s learning software. Many schools must run the software from the server and it requires admin privileges to run. why not put it in a root jail?

The dirty solution is to use MS's virtualization software to run it on a virtual machine. Which is inelegant but it works I guess.

*SIGH*

On another note, I got some more information on MS's Bit blocker.

Bit blocker uses ether Microsoft’s TPM (Trusted Platform Module) to store an encryption key to unlock the disk at boot time.
Alternatively you can use a USB key drive to store the key. What this does is prevent some one from yanking the hard drive and digging out your data. The info is fair game once it is started, but you have server 2003 and Vista's security to contend with at that point.

Bit blocker creates a backup key when you setup the disk so that’s your only alternative if you lose the login key.
EFS which is encrypted files on the NTFS file system are encrypted with the users personal certificate AND their local administrator (if a stand alone machine) or the network administrators certificate (if in a domain). Given the reports that The federal government required MS to include keys for their own use I wouldn't put it past them to have included that too though I don’t have any evidence confirming my suspicions.

Bit blocker seems like a neat idea, it relies on the physical security of the TPM or a USB keychain. Another layer of security for physical protection cant hurt I guess. EFS I find useful only for keeping small children out of files they ought not be seeing. It has way too much big brother entwined within it to be of use to me.

Neocrypt or GPG or anything else for that matter is still the best option for WINTEL data security in my book.

Outlaw information security tools and only the outlaws will have the security tools

While doing research into Steganography I looked at a couple of sources on wikipedia on organized crime and some of their applied uses. Organized crime still hasn’t fully adopted technology but is slowly getting there. Phishing scams and other online fraud schemes are netting a pretty penny now a day.

My point is not to illustrate organized crime as a "good" example of how to do things. My point IS to illustrate how an organization that relies on absolute secrecy to exist applies the principals that we have discussed in theory into practice.

Wikipedia has a prison tattoo section explaining prison tattoos and their meaning. Prison Tattoo’s in this context are a means to communicate social status and other intentions or proclamations. Tattooed illustrations containing metaphors such as status in a criminal gang or their intention to escape is one example. Japanese Yakuza publicly display the name of their gang on their storefront and on their clothing to identify themselves as a part of a gang.

La Cosa Nostra utilized a form of slang that baffled the FBI for a long time until the full lexicon of mafia terms was eventually discovered.

These examples show how Steganography was applied to mundane speech, body art and clothing styles that in the criminal context had a different meaning. The problem with this secret communication is that though the medium was secret, the information was not and thus vulnerable to discovery and interpretation by a third party.

It also illustrated to me the fatal flaw in Steganography which is security by obscurity which is a mantra often chanted by security guru's when addressing insecure weak proprietary security systems. However this being said, Steganography DOES buy time and help overcome passive discovery so when combined with good crypto it can be a part of a balanced communication strategy. Kind of like buying a box of SUPER ULTRA SUGAR SMACKS for your kid because its the only way you can get them to have milk in their diet.

http://en.wikipedia.org/wiki/Criminal_organization
http://en.wikipedia.org/wiki/Criminal_tattoo
http://en.wikipedia.org/wiki/Steganography

Encrypted filesystem images

Introduction:
Hola boys and girls, in this article I will speak a bit about encrypted file system images. There are many different utilities out there and each modern operating system has some kind of encryption scheme for either all or parts of their file system.
This is a short list of utilities that are available to the general public. Ill cover the basics of what an encrypted file system image is and list a few publicly available implementations for your information.

This article is intended for advanced users with a well-rounded understanding of how a computer and operating systems work.

-=- ToC -=-
x.......... Introduction
1.......... What is an encrypted file system
2.......... Uses of encrypted storage
3.......... Implementations of note with feature breakdown
4.......... Summary
5.......... Works cited

-=-=-=-=-=-=-=-=-=-=-=-=-=-
1.......... What is an encrypted file system
An encrypted file system consists of two parts, the file system (an organized system of storing binary data in an organized fashion). The other part being encryption, which is scrambling data in an organized fashion so that only designated parties may view it. In this article I am speaking about a file with in a file complete with its own file system and not dependant on the file system which the physical media that the file resides on.

-=-=-=-=-=-=-=-=-=-=-=-=-=-
2.......... Uses of encrypted storage
Secret codes as a concept are well known, it allows you to speak in a public area with out the information being revealed to un-intended recipients. The Internets data privacy is only safe because no one cares to dig through the deluge of information to figure out what your doing. In the novel "Takedown" regarding the capture of Kevin Mitnick, the authorities and two over zealous private citizens proceeded to track a persons activities via packet sniffing an entire ISP. This was done transparently so no one knew his or her privacy has been violated all to hell.

Encryption has become necessary as the medium of the Internet and computers in general have been under attack by governments, multinational corporations and criminal institutions.

Encryption is not the ENTIRE answer to these threats though. Being proactive about your computer usage routines so that you minimize communicating in an un-secure fashion is very important. Protecting your computer from rogue programs and un-trusted software is also important. All this while asking yourself, "what is this information worth." If the answer is ever your life, then you have best be prepared to dedicate a sizable portion of your life to servicing the protection of that information. Security is about setting the bar for your would be intruder. Basic security keeps the honest people honest, medium security keeps the burglar at bay, and comprehensive security keeps the bogyman out. Encryption can be very effective as an effort multiplier when used correctly.

-=-=-=-=-=-=-=-=-=-=-=-=-=-
3.......... Implementations of note with feature breakdown
- 3.1 Integrated encrypted file systems (OSS/Un*x):
Native utilities within most of the free Un*x like os's have included crypto.
Most of which have the capacity to create "memory disks" or "looped file systems". The utilities typically have the option for encrypting the data.
---LINUX---
In Linux in the 2.4 series and greater a person can do the following command:
$ dd if=/dev/zero of=enc_vol.img bs=1k count=4096
$ losetup -e 3des /dev/loop0 enc_vol.img
$ mkdosfs /dev/loop0
$ mount /dev/loop0 /mnt/

This system can use XOR and DES encryption by itself, if additional encryption algorithms are compiled into the kernel then you can make use of those too. The files created in this format are compatible with FreeOTFE, which is also available on windows and some mobile devices.

*** A side note -there was a paper which was written by Jerome Etienne titled "Vulnerability in encrypted loop device for Linux". In short, this is not a problem getting access to encrypted data, but making educated guesses and moving encrypted data around in the encrypted file. Since the file system doesn’t care about what data is where so long it’s in accordance with the file system structure the changes would not be detectable to the system. This attack is classified as a Denial of service attack but could be also classified as a kind of instant replay attack. The suggestion by the author is to authenticate to each data block or authenticate the integrity of the entire file system at boot time. The truly paranoid may want to perform a hash on the encrypted file system image via a mounting and unmounting script. This is a minor issue because the integrity of the information is controlled more by safe computing practices and physical security than encryption (Etinne, 2001).

In light of the looped file system and its shortcomings dm-crypt and LUKS have been developed as an alternative.

Prerequisites: A Linux 2.6 kernel with device mapper and dm-crypt support is needed. Also install cryptsetup-luks the package and util-linux package (g-loaded, 2005).

# cryptsetup --verbose --cipher "aes-cbc-essiv:sha256" --key-size 256 \
> --verify-passphrase luksFormat /dev/mydev/zipdisk
# cryptsetup luksOpen /dev/mydev/zipdisk encr-zipdisk
# mkdosfs -v -F 16 -n "ENCR1" /dev/mapper/encr-zipdisk
# mount -t vfat -o rw /dev/mapper/encr-zipdisk /mnt/tmp/

---OPENBSD---
OpenBSD supports memory disks or Virtual Nodes and this is done by:
$ vnconfig -k svnd0 /tmp/cryptimg
Encryption key:
$ mount /dev/svnd0c /mnt
This uses the blowfish algorithm for encryption (OpenBSD, 2007).

- 3.2 Encrypted Volume Utilities for commercially desktop systems:
---Ms Windows---
NTFS file encryption is available on Microsoft Windows XP Professional and supposedly Vista Business, Premium and Ultimate on a per file basis. Ultimate supposedly has full disk encryption utilizing their trusted computing hardware (Microsoft 2007).

Typically with the standard NTFS crypto you need to be using their latest version of the NTFS file system.
-Right click on the files you intend to encrypt.
-Select advanced
-Click on the encrypt check box.

Alternatively you can use the cipher command.
c:\echo "HiR" > example.txt
c:\cipher -e c:\example.txt

Encryption in windows this way is transparent to the user, it looks to them like any other file, however its encrypted on the disk so recovery by a third party person who has direct access to the file system is unlikely.

The file system will then enable the "encrypt" attribute which keys off of your account login info. So in order to access the content you will need the person's login info.

---Apple Mac OS 10---
Mac OS 10 has encrypted volume file creation available with AES encryption (Apple, 2007).

Select Macintosh HD -> Applications -> Utilities -> Disk Utility -> File -> New -> Blank Disk image
... Then put in the file name (ex. file)
-> select encryption -> AES-128 -> put in the password -> DONE!

Whenever you click on the image it will mount and ask for your password (assuming you don't put it in your keychain).

Of course this can be done in the command shell too.
$ hdiutil create -size 10m -encryption AES-128 -stdinpass test
Enter disk image passphrase:
...............................................................................
created: /Users/jkershner/Desktop/test.dmg
$ hdiutil attach test

- 3.3 Third Party disk encryption systems:
http://www.truecrypt.org/
Can create layered encrypted file systems images with a form of segnagraphy which a user can use a panic password to display the outer non-sensitive disk image, and a normal password for normal access to the disk image. It also can use file keys, which are existing files located anywhere on the computer, which the program uses as part of the authentication process. It can either use files on the hard drive or it can directly access devices such as hard drive partitions, entire disks or jump drives. In addition to secure file access by reading encrypted data in packets and keeping it in memory so that it does not hit the disk in unencrypted form. This is a free utility available on Windows and Linux platforms (TrueCrypt Foundation, 2007).

http://www.freeotfe.org/
Operates under both PC (MS Windows 2000/XP) and PDA (Windows Mobile 2003/2005) platforms Linux compatibility (Crypto loop "losetup", dm-crypt and LUKS supported) "Hidden" volumes may be concealed within other FreeOTFE volumes, providing "plausible deniability" FreeOTFE volumes have no "signature" to allow them to be identified as such Encrypted volumes can be either file or partition based (Dean, 2007).

- 3.4 Steganographic features
The most compelling features are the features offered in some of the 3rd party utilities which use a false nested file system image which is accessible with a panic password incase you are cohersed into giving the password so that at this first glance there would be plausible deniability (Dean, 2007)(TrueCrypt Foundation, 2007).

Simply renaming the encrypted volume file to appear as something else (such as an MP3 or a JPEG) requires the use of a 3rd party stegnagraphy utility such as Jsteg(Guillermito, 2004). Unfortunately there are ways of detecting this kind of embedding in images and possibly in other kinds of stegnagraphic containers formats (Raggo, 2007)(Fridrich, Goljan and Hogea 2006).
-=-=-=-=-=-=-=-=-=-=-=-=-=-
4.......... Summary

We have glossed over several methods of securely storing sensitive information. Combining these methods with other methods of securing information physically, electronically (through ciphering) and through safe computing practices you should have a fighting chance at keeping your data from prying eyes. Granted the data we are protecting is usually not as valuable as we think nor so worthless as to not disserve our attention to keeping it safe. A little paranoia can be healthy.

-=-=-=-=-=-=-=-=-=-=-=-=-=-
5.......... Works cited

Jessica Fridrich, Miroslav Goljan, Dorin Hogea. "Steganalysis of JPEG Images: Breaking the F5
Algorithm." (April 2006)
http://www.ws.binghamton.edu/fridrich/Research/f5.pdf

Guillermito. "Extracting data embedded with JSteg." (February 2004)
http://www.guillermito2.net/stegano/jsteg/index.html

Raggo, Michael. (Accessed February 2007)
http://www.spy-hunter.com/stego.html

Etienne, Jerome ".Vulnerability in encrypted loop device for Linux" (December 2001)
http://www.off.net/~jme/loopdev_vul.html

Shimomura, Tsutomu and Markoff, John. "Takedown: The Pursuit and Capture of Kevin Mitnick, America's Most Wanted Computer Outlaw-By the Man Who Did It." Warner Books Inc (December 1996). ISBN-13: 978-0786889136

-3rd Party Security Products
Dean, Sarah "Free OTFE." (Accessed February 2007)
http://www.freeotfe.org/

TrueCrypt Foundation websirte. (Accessed February 2007)
http://www.truecrypt.org/

-Opperating systems, security feature implementation and howto's

Microsoft Inc. "Encrypting File System overview." (Accessed February 2007)
http://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/encrypt_overview.mspx?mfr=true

Apple Corp. "Mac OS X: How to create a password-protected (encrypted) disk image." (Accessed February 2007)
http://docs.info.apple.com/article.html?artnum=107333

g-loaded.eu, "Encrypt devices using dm-crypt and LUKS." (November 2005)
http://www.g-loaded.eu/2005/11/10/encrypt-devices-using-dm-crypt-and-luks/

OpenBSD foundation. (Accessed 2007)
http://www.openbsd.org

-=-=-=-=-=-=-=-=-=-=-=-=-=-EOF-=-=-=-=-=-=-=-=-=-=-=-=-=-