Cryptology ePrint Archive: Report 2014/155

Honey Encryption: Security Beyond the Brute-Force Bound

Ari Juels and Thomas Ristenpart

Abstract: We introduce {\em honey encryption} (HE), a simple, general approach to encrypting messages using low min-entropy keys such as passwords. HE is designed to produce a ciphertext which, when decrypted with any of a number of {\em incorrect} keys, yields plausible-looking but bogus plaintexts called {\em honey messages}. A key benefit of HE is that it provides security in cases where too little entropy is available to withstand brute-force attacks that try every key; in this sense, HE provides security beyond conventional brute-force bounds. HE can also provide a hedge against partial disclosure of high min-entropy keys.

HE significantly improves security in a number of practical settings. To showcase this improvement, we build concrete HE schemes for password-based encryption of RSA secret keys and credit card numbers. The key challenges are development of appropriate instances of a new type of randomized message encoding scheme called a {\em distribution-transforming encoder} (DTE), and analyses of the expected maximum loading of bins in various kinds of balls-and-bins games.

Category / Keywords: secret-key cryptography /

Original Publication (with major differences): IACR-EUROCRYPT-2014

Date: received 28 Feb 2014

Contact author: ajuels at gmail com

Available format(s): PDF | BibTeX Citation

Version: 20140301:155206 (All versions of this report)

Short URL: ia.cr/2014/155

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