recoding vs secret writing

recoding and secret writing both are nouns.

Word	Noun	Adjective	Verb	Adverb
recoding	Yes	No	No	No
secret writing	Yes	No	No	No

As nouns, secret writing is a hypernym of recoding; that is, secret writing is a word with a broader meaning than recoding:

Other hypernyms of recoding include coding, cryptography, steganography.

recoding (noun)	secret writing (noun)
converting from one code to another	act of writing in code or cipher
	a piece of writing in code or cipher