Deterministic Public-Key Encryption Under Continual Leakage

Abstract

Deterministic public-key encryption, introduced by Bellare, Boldyreva, and O'Neill (CRYPTO 2007), is an important technique for searchable encryption; it allows quick, logarithmic-time, search over encrypted data items. The technique is most effective in scenarios where frequent search queries are performed over a huge database of unpredictable data items. We initiate the study of deterministic public-key encryption (D-PKE) in the presence of leakage. We formulate appropriate security notions for leakage-resilient D-PKE, and present constructions that achieve them in the standard model. We work in the continual leakage model, where the secret-key is updated at regular intervals and an attacker can learn arbitrary but bounded leakage on the secret key during each time interval. We, however, do not consider leakage during the updates. Our main construction is based on the (standard) linear assumption in bilinear groups, tolerating up to 0.5 − o(1) fraction of arbitrary leakage. The leakage rate can be improved to 1 − o(1) by relying on the SXDH assumption.At a technical level, we propose and construct a "continual leakage resilient" version of the all-but-one lossy trapdoor functions, introduced by Peikert and Waters (STOC 2008). Our formulation and construction of leakage-resilient lossy-TDFs is of independent general interest for leakage-resilient cryptography.

Machine Learning Based Cyber Attacks Targeting on Controlled Information: A Survey

“…Stealing controlled secret keys for authentication. Secret keys are used to encrypt and decrypt sensitive messages [18,63,139]. Reconstructing the cryptographic keys means that one host is authenticated to read the message in some cases [46,56,106].…”

Continuous Leakage Resilient Lossy Trapdoor Functions

“…Based on the work of Brakerski et al [16], Koppula et al [23] firstly gave the security model of lossy trapdoor functions under continuous leakage and presented the lossy trapdoor functions against continuous leakage, which is a base of the deterministic public key encryption against continuous leakage. Their security model is mainly based on the all-but-one (ABO) LTFs of Peikert and Waters in [1].…”

“…Though Koppula et al [23] has introduced a notion of LTFs resilient to continual memory leakage, their notion was mainly based on the all-but-one (ABO) LTFs of Peikert and Waters in [1]. The new notion, which will be presented as follows, is mainly based on the LTFs structure of Qin and Liu et al [24], which is slightly different from the one introduced by Peikert and Waters in [1].…”

“…Compared with the other known CLR-LTFs constructions introduced by Koppula et al [23], we give an efficiency comparison as below (Table 1). |m| denotes the length of the encrypted massage; n ≈ Θ(κ) where κ is the security parameter; N is an RSA modulus which will be explained by detail in Section 6; α ≥ 1 is a nature number; DDH means Decisional Diffie-Hellman assumption; SXDH means Symmetric External Diffie-Hellman assumption; DCR means Decisional Composite Residuosity assumption.…”