## Cryptology ePrint Archive: Report 2017/953

Threshold Kleptographic Attacks on Discrete Logarithm Based Signatures

George Teseleanu

Abstract: In an $\ell$ out of $n$ threshold scheme, $\ell$ out of $n$ members must cooperate to recover a secret. A kleptographic attack is a backdoor which can be implemented in an algorithm and further used to retrieve a user's secret key. We combine the notions of threshold scheme and kleptographic attack to construct the first $\ell$ out of $n$ threshold kleptographic attack on discrete logarithm based digital signatures and prove its security in the standard and random oracle models.

Category / Keywords: public-key cryptography, kleptography, threshold cryptography, information hidding, SETUP attacks

Original Publication (with major differences): Latincrypt 2017

Date: received 27 Sep 2017, last revised 19 Dec 2018

Contact author: george teseleanu at yahoo com

Available format(s): PDF | BibTeX Citation

Short URL: ia.cr/2017/953

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