WordNet (r) 3.0 (2006):

decoding
    n 1: the activity of making clear or converting from code into
         plain text; "a secret key or password is required for
         decryption" [syn: decoding, decryption, decipherment]

Moby Thesaurus II by Grady Ward, 1.0:

91 Moby Thesaurus words for "decoding":
   EDP, accomplishment, allegorization, amplification, answer,
   ascertainment, bilingual text, bit, channel, clarification, clavis,
   clearing up, communication explosion, communication theory,
   cracking, crib, data retrieval, data storage, decipherment,
   demonstration, demythologization, denouement, determination,
   disentanglement, editing, electronic data processing, elucidation,
   emendation, encoding, end, end result, enlightenment, entropy,
   euhemerism, exegesis, exemplification, explanation, explication,
   exposition, expounding, faithful translation, finding, finding-out,
   free translation, gloss, glossary, illumination, illustration,
   information explosion, information theory, interlinear,
   interlinear translation, interpretation, issue, key, light,
   loose translation, metaphrase, noise, outcome, paraphrase, pony,
   rationale, reason, redundancy, resolution, resolving, restatement,
   result, rewording, riddling, signal, simplification, solution,
   solving, sorting out, transcription, translation, transliteration,
   trot, unlocking, unraveling, unriddling, unscrambling, unspinning,
   untangling, untwisting, unweaving, upshot, working, working-out