undecryptable

Cannot be decoded

Undecryptable describes something that cannot be decrypted—code or encrypted data that resists all attempts to convert it back to readable form.

The term appears in discussions of secure communications and data protection: The messages were undecryptable without the private key.

Sometimes used loosely to mean extremely difficult rather than truly impossible to decrypt.

mysterious

enigma

Something hard to fathom

inscrutableImpossible to understand
unfathomableBeyond comprehension or measurement
impenetrableImpossible to pass through

arcane · indecipherable · incomprehensible · opaque · obscure · veiled · hidden · secrets · puzzling · baffling

cryptographic

cipher

Hidden writing system

ciphertextEncoded, unreadable message
algorithmFinite problem-solving procedure
keyLock-opening device

cryptanalysis · codebreaker · plaintext · AES · RSA · symmetric · asymmetric · steganography · hash · authentication

secure

protected

Kept from harm

lockedFastened with a mechanism
safeguardedKept from harm
impregnableImpossible to capture

inviolable · tamper-proof · airtight · uncrackable · unbreachable · fortified · sealed · inaccessible · blocked · firewalled

Opposites

decipherability

undecryptabledecryptable

Able to be unscrambled

decipherable · crackable · decodable · breakable · solvable

information accessibility

undecryptableplaintext

Unencoded readable information

clear · unencrypted · open · transparent · exposed

Family

undecrypted, decrypt, decrypts, decrypted, decrypting, decryptable, decryption, encrypt, encrypts

Familiarity: Top 1,000,000
Profile: Used worldwide · Timeless · Abstract · Rated G