decoding vs decipherment

decoding and decipherment both are nouns.

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

As nouns, decoding and decipherment are synonyms defined as:

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

Other synonyms of decoding include decryption.

decoding (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