sb. [ad. F. contrechifre (Cotgr.) = It. contracifera, Sp. contracifra: see COUNTER- 8.] A cipher that answers to and explains another; the key to a cipher.
1598. Florio, Contracifera, a countercifer, a cifer that doth answer another.
1611. Cotgr., Contrechifre, a countercypher; a note explanatorie of particular cyphers.
1651. Life Father Sarpi (1676), 70. Where in a secret Cabinet there were Letters found … with Ciphers and Counterciphers.
So † Countercipher v. [ad. obs. F. contrechifrer ‘to answer cyphers with cyphers; also, to expound cyphers’ (Cotgr.), It. contraciferare (Florio).]
1611. Florio, Contraciferáre, to countercipher.
