cryptography vs cryptographical

cryptography is a noun but cryptographical is not a noun.

Word	Noun	Adjective	Verb	Adverb
cryptography	Yes	No	No	No
cryptographical	No	Yes	No	No

cryptography (noun)	cryptographical (noun)
act of writing in code or cipher
the science of analyzing and deciphering codes and ciphers and cryptograms

cryptography (adjective)	cryptographical (adjective)
	of or relating to cryptanalysis