'a simple parser of ARF compliant FBL complaints, which normalizes the email complaints and generates a 6-tuple n-gram version of the message. These n-grams are stored in a Redis database, keyed by the file in which they can be found. An inverse index also exists that allow you to find all messages containing a particular n-gram word.'

ie. TinEye and other "images like this one" search engines. nice explanation

'a (python) library and a tool to clusterize similar files using fuzzy hashing techniques. This project is inspired by the well known tool ssdeep.' Via Nelson

good to know (via Jeremy)

why HMAC is more secure than secret-suffix and secret-prefix keyed hashing. good to know