One thing that bothers me about OpenSSL is the lack of commandline support for AEAD ciphers, specifically AES in CCM and GCM block modes. Why does this matter? Suppose you want to save an encrypted file to disk, without GnuPG, because you don't want to get into key management. Further, suppose you want to send […]
I can't imagine there are a lot of uses for using digest algorithms in spreadsheets, but I came up with one, and I really wished I had access to them. Seeing as though most spreadsheet applications don't ship one, I figured I would create my own. Mostly, I use Google for my document processing and […]
I recently submitted a bug to the Vim project about its Blowfish encryption not using authentication. Bram Moolenaar, the lead developer of Vim, responded about using checksums and digital signatures. I hope he doesn't mind me using him as an example here, but I want to quote the relevant bits (emphasis mine): The encryption is […]
Recently, the Bitcoin mining rate surpassed 1 exahash per second, or 1 quintillion SHA-256 hashes per second. If we do some quick math, we can determine the following: If SHA-1 collisions can be found in 2^65.3 hashes, that's one SHA-1 collision found every 45 seconds. Every combination of bits can be flipped in an 84-bit […]
File this under the "I'm bored and have nothing better to do" category. While coming into work this morning, I was curious if I could use my monitors as a cryptographically secure pseudorandom number generator (CSPRNG). I don't know what use this would have, if any, as your GNU/Linux operating system already ships a CSPRNG […]
Background I've been a long-time KeepassX user, and to be honest, I don't see that changing any time soon. I currently have my password database on an SSH-accessible server, of which I use kpcli as the main client for accessing the db. I use Keepass2Android with SFTP on my phone to get read-only access to […]
I hang out in ##crypto in Freenode, and every now and then, someone will ask about the security of multiple encryption, usually with the context that AES could be broken in the near future. When talking about multiple encryption, they are usually referring to cascade encryption which has the form of: CT = Alg_B(Alg_A(M, key_A), […]
This post is inspired by a discussion in irc://irc.freenode.net/#gnupg about Keybase and a blog post by Filippo Valsorda. I was curious just exactly how my private key is encrypted. Turns out, gpg(1) can tell you directly: $ gpg --output /tmp/secret-key.gpg --export-secret-keys 0x22EEE0488086060F $ gpg --list-packets /tmp/secret-key.gpg :secret key packet: version 4, algo 17, created 1095486266, […]
I have been a long proponent of OpenPGP keys for a way to communicate securely. I have used my personal key for signing emails since ~ 2005. I have used my key at dozens and dozens of keysigning parties. I have used my key to store account passwords and credentials with vim(1), Python, and so […]
Recently, the Password Hashing Competition announced its winner, namely Argon2, as the future of password hashing. It's long since been agreed that using generic-purpose cryptographic hashing algorithms for passwords is not a best practice. This is due to their speed. Cryptographic hashing algorithms are designed to be lighting fast, while also maintaining large margins of […]
As you know, I am a cryptography hobbyist. More specifically, I have an interest in pencil and paper ciphers, also referred to as "hand ciphers" or "field ciphers". Since Bruce Schneier released his Solitaire Cipher for Neal Stephenson's book "Cryptonomicon" (known in the book as "Pontifex"), I have had a real desire to learn hand […]
Yesterday, I received my Kidekin TRNG hardware random number generator. I was eager to purchase this, because on the Tindie website, the first 2 people to purchase the RNG would get $50 off, making the device $30 total. I quickly ordered one. Hilariously enough, I received a letter from the supplier that I was their […]
A couple days ago, I put up a post about using the Realtek SDR dongles as a hardware true random number generator. I only tested the randomness of a 512 MB file. I thought this time, I would but a bit more stock into it. In this case, I let it run for a while, […]
An rtl-sdr dongle allows you to receive radio frequency signals to your computer through a software interface. You can listen to Amateur Radio, watch analog television, listen to FM radio broadcasts, and a number of other things. I have a friend to uses it to monitor power usage at his house. However, I have a […]
This morning, my family and I went swimming at the community swimming center. Unfortunately, I couldn't find my key-based lock that I normally take. However, I did find my Master combination lock, but couldn't recall the combination. Fortunately, I knew how to find it. I took this lock with me to lock my personal items […]