de·ci·pher 
(dĭ-sīfər)
(dĭ-sīfər)tr.v. de·ci·phered, de·ci·pher·ing, de·ci·phers
1. To read or interpret (ambiguous, obscure, or illegible matter).
2. To convert from a code or cipher to plaintext; decode.
de·cipher·a·ble adj.
de·cipher·er n.
de·cipher·ment n.