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{ Category Archives } Cryptology

Making Sense of Hashed Hosts in ~/.ssh/known_hosts

I don’t expect you to follow this post completely, but it’s so amazingly cool, I have to blog it. Consider the hashed sections of ~/.ssh/known_hosts file for (recent) OpenSSH clients, not including the public key parts: |1|kFJT5z0x3ndyutgZ4E5pRk+ORBA=|hzXvdYUudo+qK9BGlFWtSAUXlXc= |1|8wo1+FO0hkATPgQZoeNHeIlvAjw=|dt/a9jz9CnLKP72j+Jr8MKMjgEE= |1|pvBQEKEGLnH0RCJr+8Dmqqnvlrs=|fJJvjyG/TmHFnuIX57nDThq/C4M= |1|HKV4DzgDkajXoUHf9B82JBu7J10=|c/K+MdJvWaZeJFs/W7iqhqo0wvE= |1|rtvQhRVnNanQZYkLUMbjoBGNhn0=|0U6a1LUQqLL6P1T2Wji3VWw69pw= |1|0ziSYi4c+xBXGEBZcNN1LMhYUc4=|qRSN5GSPyQi+fmaVz2zNwkmKoy8= |1|6nv6Vpk3AYgICHxJGVgVdsYRuq0=|fBNOIz1l3RW+N61jyDPunKX9n7E= |1|+b4uA+Mq7RHRAFW21qv8aO3rIRs=|1eizMri01IxEKrXquBnwTYP61Ow= |1|BkB0PZu2qtsLID/Ibe/D68gANQU=|qW6uAzcpecOOKNI4zEvngyfpGkI= |1|n+QrRn7QXeAJ5hRe2M8v8IspihE=|EqUxXdSeIF1cl1fQjl5zILebkGY= |1|BOKuKnWojy028tJf9Y671lws0d0=|SuBQJmJZp5JNVYG/rP9yb9ZhJcE= |1|WACsxtodOiM89kf4rNPLgF1CXZ4=|UTccVeLDZJF3wlH8V05XJNlsOBw= |1|o6FFoirXYblM7wBMdeJDYGMPI58=|5jJB7T7itY702ZHHByXtSpGk9SE= The column fields are similar to [...]

2011 12 30 Security Comments (0)

OpenSSH Best Practices

This post comes from Matt Taggart, who put together a document about the best practices for using OpenSSH. A lot of the points brought up in that document rang the bells of common sense, and are so good, it’s worth blogging about in hopes that the points mentioned therein reach as many as possible. I’ve [...]

2011 07 22 Linux
Security Comments (7)

Convert Text To Base-64 By Hand

When I was a kid, I had this fascination with cryptography. I learned and used, as most kids to, the Caesar cipher first (using my trusty Captain Crunch Decoder Ring), then later learned and used the Affine cipher. It was great for passing notes in class when I was in elementary and secondary education. I [...]

2011 04 06 Security Comments (3)

Verifying Hashcash Tokens With Mutt

Just five days ago, I blogged about minting Hashcash tokens in Mutt using a Python script (make sure you check that page for any updates to the source if you’re using it). Well today, I finished writing my verification script. It takes some additional changes to your ~/.muttrc, which I’ll outline here, and it requires [...]

2011 03 29 Python
Scripting
Security Comments (3)

Hashcash and Mutt

Introduction I wanted to used Hashcash with Mutt, for nothing more than a curiosity to see if it generates any discussion, and to see if people notice. Further, I’m a big crypto advocate, and while Hashcash isn’t exactly crypto, it’s highly related to it, and uses it. Regardless, I wanted to see if I could [...]

2011 03 24 Python
Scripting
Security Comments (6)

Bitlbee and OTR

I’m actually surprised that I haven’t blogged about this before, seeing as though I use it daily. Further, seeing as though I seem to be on a security blogging trip, it only seems fitting to discuss OTR support in Bitlbee now. OTR, or Off-The-Record messaging is the ability to have encrypted and authenticated communication with [...]

2011 03 08 Security Comments (4)

Elliptic Curve Cryptography in OpenSSH

I’ve been meaning to add this as a post, as it’s light and quick, but as the release of OpenSSH 5.7, Elliptic Curve Cryptography has been implemented. Why should you care? The generated keys are substantially smaller, the algorithm is faster and lighter, giving a break to slower CPUs and the cryptanalysis hasn’t shown any [...]

2011 02 17 Security Comments (7)

GnuPG Up And Close

Every GNU/Linux distribution ships with GnuPG by default. While they all don’t ship with the same GUI frontend, they do ship with the the same CLI backend. So, we’ll be interfacing with that throughout this informational session. I’m not presenting this as anything necessarily useful. Rather, I hope you find it informational/educational, and learn a [...]

2009 06 08 Linux
Security Comments (8)

Using GnuPGv2

I’ve moved to GnuPG version 2, mainly just out of curiosity. I have read the feature list between version 1 and 2. Apparently, version 2 supports the same algorithms, completely backwards-compatible with version 1, more modular and supports additional functionality. So, with that, my GPG key has been re-exported using version 2. It’s available on [...]

2008 08 12 Comments (5)

Update My Public Key

At your earliest convenience, you’ll need to update my public key in your keyring. You can grab the cleaned copy from my site, or your can get an uncleaned copy from either the Ubuntu keyserver or the PGP keyserver. Please do not use the MIT PGP keyserver, until I can get straightened out why they [...]

2008 01 22 Comments (3)

MIT PGP Keyserver

I just discovered, after spending some time trying to get my public key uploaded to the MIT PGP keyserver that they do not support photos in public keys. I find this rather unfortunate, as photos add a level of security to the key. This also means that any IDs that I add to my key [...]

2008 01 05 Comments (1)

GnuPG Turns 10

Happy Birthday to the GnuPG team and community. GnuPG turns 10 today! For those caught unaware, GnuPG was designed to be a Free Software implementation of PGP, removing the patented algorithms, such as RSA and IDEA, and replacing them with Free Software algorithms, such as Blowfish and ElGamal. Being a strong advocate of GnuPG and [...]

2007 12 20 OSS Comments (2)

A Perfect Reason Why You Should Digitally Sign Emails

According to a supposed email from lead developer of PHP Jani Taskinen, he’s outta here, and not looking back. Goodbye PHP, goodbye cruel world! is the theme of his email. From: Jani Taskinen Subject: Good bye. Group: php.internals Date: Thu Jul 27 20:28:45 2006 Thank you all for the last 6 years or so. It [...]

2006 07 28 Security Comments (1)

Public Keyservers

As mentioned in my last post, I don’t generally use keyservers. I would much rather just email the key or leave it posted on my blog. However, with that said, I do have my key published to the 3 most popular keyservers on the web, with the first as my default in both Seahorse and [...]

2006 06 25 Comments (0)

My GnuPG Public Key

For those of you who read my blog and wonder if I have a GPG key, well your in luck! I have had a key since Glen, a friend of mine, introduced me the world of encryption and security in September 2004, and my life hasn’t been the same since. I used to sign all [...]

2006 06 24 Comments (0)