Separations in circular security for arbitrary length key cycles

Venkata Koppula, Kim Ramchen, Brent Waters

Research output: Chapter in Book/Report/Conference proceedingConference PaperResearchpeer-review

14 Citations (Scopus)

Abstract

While standard notions of security suffice to protect any message supplied by an adversary, in some situations stronger notions of security are required. One such notion is n-circular security, where ciphertexts Enc(pk1, sk2), Enc(pk2, sk3), . . . , Enc(pkn, sk1) should be indistinguishable from encryptions of zero. In this work we prove the following results for n-circular security, based upon recent candidate constructions of indistinguishability obfuscation [18,16] and one way functions: For any n there exists an encryption scheme that is IND-CPA secure but not n-circular secure. There exists a bit encryption scheme that is IND-CPA secure, but not 1-circular secure. If there exists an encryption system where an attacker can distinguish a key encryption cycle from an encryption of zeroes, then in a transformed cryptosystem there exists an attacker which recovers secret keys from the encryption cycles. The last result is generic and applies to any such cryptosystem.

Original languageEnglish
Title of host publicationTheory of Cryptography
Subtitle of host publication12th Theory of Cryptography Conference, TCC 2015 Warsaw, Poland, March 23-25, 2015 Proceedings, Part II
EditorsYevgeniy Dodis, Jesper Buus Nielsen
Place of PublicationBerlin Germany
PublisherSpringer
Pages378-400
Number of pages23
ISBN (Electronic)9783662464960
ISBN (Print)9783662464977
DOIs
Publication statusPublished - 2015
Externally publishedYes
EventTheory of Cryptography Conference 2015 - Warsaw, Poland
Duration: 23 Mar 201525 Mar 2015
Conference number: 12th
https://www.iacr.org/workshops/tcc2015/

Publication series

NameLecture Notes in Computer Science
PublisherSpringer
Volume9015
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349

Conference

ConferenceTheory of Cryptography Conference 2015
Abbreviated titleTCC 2015
CountryPoland
CityWarsaw
Period23/03/1525/03/15
Internet address

Cite this

Koppula, V., Ramchen, K., & Waters, B. (2015). Separations in circular security for arbitrary length key cycles. In Y. Dodis, & J. B. Nielsen (Eds.), Theory of Cryptography : 12th Theory of Cryptography Conference, TCC 2015 Warsaw, Poland, March 23-25, 2015 Proceedings, Part II (pp. 378-400). (Lecture Notes in Computer Science; Vol. 9015). Springer. https://doi.org/10.1007/978-3-662-46497-7_15