hashing
Hashes are a bit like fingerprints for data. A given hash uniquely represents a file, or any arbitrary collection of data. At least in theory. This is a 128-bit MD5 hash you're looking at above, so it can represent at most 2128 unique items, or 340 trillion trillion
security
I just posted a new article on CodeProject, .NET Encryption Simplified. In my spare time over the last 6 months, I’ve delved deeper and deeper into the System.Security.Cryptography classes. And you know what I learned? Cryptography is hard. Anyway, I now have a heavily documented wrapper class