Format Preserving Encryption using the scheme FE1 from the paper "Format-Preserving Encryption" by Bellare, Rogaway, et al (http://eprint.iacr.org/2009/251)
Encrypt X from and onto the group Z_n using key and tweak
a random key
will modify the ciphertext (think of as an IV)
See Implementation
Format Preserving Encryption using the scheme FE1 from the paper "Format-Preserving Encryption" by Bellare, Rogaway, et al (http://eprint.iacr.org/2009/251)
Encrypt X from and onto the group Z_n using key and tweak