Handling Adaptive Compromise for Practical Encryption Schemes

Joseph Jaeger; Nirvan Tyagi

Paper 2020/765

Handling Adaptive Compromise for Practical Encryption Schemes

Joseph Jaeger

, University of Washington

Nirvan Tyagi

, Cornell University

Abstract

We provide a new definitional framework capturing the multi-user security of encryption schemes and pseudorandom functions in the face of adversaries that can adaptively compromise users' keys. We provide a sequence of results establishing the security of practical symmetric encryption schemes under adaptive compromise in the random oracle or ideal cipher model. The bulk of analysis complexity for adaptive compromise security is relegated to the analysis of lower-level primitives such as pseudorandom functions. We apply our framework to give proofs of security for the BurnBox system for privacy in the face of border searches and the in-use searchable symmetric encryption scheme due to Cash et al. In both cases, prior analyses had bugs that our framework helps avoid.

Note: This update expands the discussion of related work and provides a strengthened definition of equivocable encryption to fix subtle issues in the prior definition.

Metadata

Available format(s): PDF
Category: Secret-key cryptography
Publication info: A major revision of an IACR publication in CRYPTO 2020
DOI: 10.1007/978-3-030-56784-2_1
Keywords: adaptive security ideal models searchable symmetric encryption
Contact author(s): jsjaeger @ cs washington edu
tyagi @ cs cornell edu
History: 2023-07-18: revised; 2020-06-24: received; See all versions
Short URL: https://ia.cr/2020/765
License: CC BY

BibTeX

@misc{cryptoeprint:2020/765,
      author = {Joseph Jaeger and Nirvan Tyagi},
      title = {Handling Adaptive Compromise for Practical Encryption Schemes},
      howpublished = {Cryptology {ePrint} Archive, Paper 2020/765},
      year = {2020},
      doi = {10.1007/978-3-030-56784-2_1},
      url = {https://eprint.iacr.org/2020/765}
}