cryptograph vs device

cryptograph and device both are nouns.

Word	Noun	Adjective	Verb	Adverb
cryptograph	Yes	No	No	No
device	Yes	No	No	No

As nouns, device is a hypernym of cryptograph; that is, device is a word with a broader meaning than cryptograph:

cryptograph (noun)	device (noun)
a device for deciphering codes and ciphers	any clever maneuver
a piece of writing in code or cipher	an instrumentality invented for a particular purpose
a secret method of writing	an emblematic design (especially in heraldry)
	any ornamental pattern or design (as in embroidery)
	something in an artistic work designed to achieve a particular effect