Keyczar simplifies implementing of cryptographic functions in applications which typically involves selecting a cryptographic algorithm along with the key length and operation mode, handling of initialization vectors, rotation of keys and the signing of ciphertexts. Keyczar selects “safe defaults” for all these options resulting in fewer mistakes from the developer.

Examples from Google:

Java
Crypter crypter = new Crypter(“/path/to/your/keys”);
String ciphertext = crypter.encrypt(“Secret message”);

Python
crypter = Crypter.Read(“/path/to/your/keys”);
ciphertext = crypter.Encrypt(“Secret message”);

Other open source security projects from Google include RATproxy and Flayer