decryption vs decipherment

decryption and decipherment both are nouns.

Word	Noun	Adjective	Verb	Adverb
decryption	Yes	No	No	No
decipherment	Yes	No	No	No

As nouns, decryption and decipherment are synonyms defined as:

decryption and decipherment: the activity of making clear or converting from code into plain text

Other synonyms of decryption include decoding.

decryption (noun)	decipherment (noun)
the activity of making clear or converting from code into plain text	the activity of making clear or converting from code into plain text