Are modes of operation algorithms practical? I took a cryptography class back in college, and now that I am working my 1st career one of the things currently on my plate is coming up with an algorithm to encrypt data before it's placed on the server (In this case it's pretty sensitive info). I remember different modes of operation from that class like cipher block chaining and things of the like. I know that some of them are pretty hard to crack, but since they are so commonly known is it even practical to consider using something like that as an encryption method considering the algorithms for encryption and decryption are commonly known (from a security perspective)?
I know that some of them are pretty hard to crack, but since they are so commonly known is it even practical to consider using something like that as an encryption method considering the algorithms for encryption and decryption are commonly known (from a security perspective)?


In fact, this is exactly what we want.

Schneier's law


  Anyone, from the most clueless amateur to the best cryptographer, can create an algorithm that he himself can't break.


That is why it is crucial that the algorithms be made public. If the only information I keep secret from you is a relatively short key (128-bits isn't much), and you still cannot break the cipher, then one could argue that the cipher is stronger than one where you have to keep a few megabytes (the source code) protected.