### Forward-Security under Continual Leakage

Mihir Bellare, Adam O'Neill, and Igors Stepanovs

##### Abstract

Current signature and encryption schemes secure against continual leakage fail completely if the key in any time period is fully exposed. We suggest forward security as a second line of defense, so that in the event of full exposure of the current secret key, at least uses of keys prior to this remain secure, a big benefit in practice. (For example if the signer is a certificate authority, full exposure of the current secret key would not invalidate certificates signed under prior keys.) We provide definitions for signatures and encryption that are forward-secure under continual leakage. Achieving these definitions turns out to be challenging, and we make initial progress with some constructions and transforms.

Available format(s)
Category
Public-key cryptography
Publication info
Published elsewhere. MAJOR revision.16th International Conference on Cryptology and Network Security (CANS 2017)
Keywords
leakage-resilient cryptographyforward securitydigital signaturespublic-key encryption
Contact author(s)
istepano @ eng ucsd edu
History
2017-10-10: revised
See all versions
Short URL
https://ia.cr/2017/476

CC BY

BibTeX

@misc{cryptoeprint:2017/476,
author = {Mihir Bellare and Adam O'Neill and Igors Stepanovs},
title = {Forward-Security under Continual Leakage},
howpublished = {Cryptology ePrint Archive, Paper 2017/476},
year = {2017},
note = {\url{https://eprint.iacr.org/2017/476}},
url = {https://eprint.iacr.org/2017/476}
}

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