Definition of decrypt in US English:



[with object]
  • Make (a coded or unclear message) intelligible.

    ‘the computer can be used to encrypt and decrypt sensitive transmissions’
    • ‘Everybody will know the information has come from you because only your public key can decrypt a message that has been encrypted using your private key.’
    • ‘But once you have the right key, it takes less than a fraction of a second to prove that the key is the correct key: All you do is decrypt the message.’
    • ‘This key would allow the government to decrypt messages as needed, purportedly after seeking and obtaining a warrant.’
    • ‘An encryption algorithm is a mathematical equation containing the message being encrypted or decrypted.’
    • ‘Many historians think that a secret Soviet message sent in 1945 (later decrypted by the Venona project) identifies Hiss by a code name.’
    • ‘The Aegis system allows a user to encrypt or decrypt a message by just hitting a button and entering a password, and the company says the password part of the process may be phased out soon.’
    • ‘It should be easy to encrypt and decrypt messages with the key (which must be kept secret) but difficult to do so without it.’
    • ‘During 1942, the US Military Attaché in Cairo, through transmissions decrypted by Italian intelligence, gave him invaluable operational intelligence.’
    • ‘I had a top-secret clearance and would have been part of the team of codebreakers decrypting the message that authorized the use of the ship's nuclear weapons.’
    • ‘Another thing that will come along - probably after more than a decade or two - is quantum cryptanalysis, where you would use a quantum computer to decrypt existing codes.’
    • ‘Second, when they cannot decrypt the alien code, he gives her the key to the mystery.’
    • ‘By 1944, over 4,000 German messages were being decrypted daily at Bletchley Park.’
    • ‘Failure to comply with a decryption notice will be a criminal office, unless the individual concerned can prove he or she did not have the ability to decrypt the message for any reason, such as losing the password.’
    • ‘Unlike DVD movies, which are encrypted on the disk and decrypted every time they're played, digital broadcast television has to be unencrypted.’
    • ‘Several seconds passed before the communication was decrypted and became intelligible.’
    • ‘With public key encryption, each person has two keys - a public one that can be disseminated freely which is used to encode messages that can subsequently only be decrypted by the private key.’
    • ‘Otherwise, he can merely decrypt the message without any additional steps or effort.’
    • ‘The Crown supplemented this with an excellent system of opening the mails (and diplomatic pouches, when available) and decrypting messages written in code.’
    • ‘Since the eavesdropper doesn't know the starting point, he can't decrypt the message.’
    • ‘A Tactical Data Encryption System TDES is a device for storing, encrypting and decrypting messages.’
    decipher, unravel, untangle, work out, sort out, piece together, solve, interpret, translate, construe, explain, understand, comprehend, apprehend, grasp
    View synonyms


  • A text that has been decoded.

    • ‘Knowledge of the Venona decrypts was actually withheld from President Truman.’
    • ‘Indeed, as I write in the book on p. 40, he kept the top-secret decrypts in what he called ‘The Magic Book,’ tucked away in the tightly-guarded Map Room of the White House.’
    • ‘This group was able to keep the secret while getting the sensitive Ultra and Magic decrypts of enemy messages.’
    • ‘Equally, the German Navy passed on decrypts of Allied traffic to Japan after 9 December 1941 only in its own cipher because of suspicions about Anglo-American inroads into Japanese systems.’
    • ‘We now know, from the Venona decrypts of Soviet intelligence traffic, that he was guilty as charged of heading a Soviet atomic espionage ring.’
    • ‘Its essence was gross and irresponsible exaggeration of a claim that we now know - from the VENONA decrypts of Soviet cables, among other sources - was true.’
    • ‘In order to protect the sensitive VENONA project, the decrypts could not be produced as evidence at trial.’
    • ‘Only in 1941 did Enigma decrypts pay dividends.’
    • ‘A combination of defectors and America's VENONA decrypts caused the collapse of the Soviet networks and the beginning of the end of the era of the ideological agent.’
    • ‘Do you think that the governor of Idaho had access to the MAGIC decrypts, and that he formulated his demand for ‘concentration camps’ on the basis of an evidence-based belief of military necessity?’
    • ‘Even when Hiss appeared in the Venona decrypts, his supporters refused to believe he was guilty.’
    • ‘But there were still some who challenged her allegations and the validity of the decrypts, calling them forgeries.’
    • ‘In a semi-polemical preface, he takes some unwarranted shots at post-Cold War studies of Soviet spying that are based on VENONA decrypts and documents from KGB and Comintern archives.’


1930s: from de- (expressing reversal) + crypt as in encrypt.