Source : Webster's Revised Unabridged Dictionary (1913)

Cryptographic \Cryp`to*graph"ic\ (kr?p`t?-gr?f"?k),
Cryptographical \Cryp`to*graph"ic*al\ (kr?p`t?-gr?f"?-kal), a.
   Relating to cryptography; written in secret characters or in
   cipher, or with sympathetic ink.

Source : WordNet®

cryptographical
     adj : of or relating to cryptanalysis [syn: {cryptanalytic}, {cryptographic},
            {cryptologic}, {cryptological}]