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作者: GCT

浏览量: 325

时间: 2019-08-19 12:01

关键词: 信息安全,Crypto,智库,GCT




Best Paper

Title:Cryptanalysis of OCB2: Attacks on Authenticity and Confidentiality

作者:Akiko Inoue,Tetsu Iwata,Kazuhiko Minematsu,Bertram Poettering

Abstrcat:We present practical attacks on OCB2. This mode of operation of a blockcipher was designed with the aim to provide particularly efficient and provably-secure authenticated encryption services, and since its proposal about 15 years ago it belongs to the top performers in this realm. OCB2 was included in an ISO standard in 2009.An internal building block of OCB2 is the tweakable blockcipher obtained by operating a regular blockcipher in XEX mode. The latter provides security only when evaluated in accordance with certain technical restrictions that, as we note, are not always respected by OCB2. This leads to devastating attacks against OCB2’s security promises: We develop a range of very practical attacks that, amongst others, demonstrate universal forgeries and full plaintext recovery. We complete our report with proposals for (provably) repairing OCB2. To our understanding, as a direct consequence of our findings, OCB2 is currently in a process of removal from ISO standards. Our attacks do not apply to OCB1 and OCB3, and our privacy attacks on OCB2 require an active adversary.

Best Young Researcher Papers

Title:Quantum cryptanalysis in the RAM model: Claw-finding attacks on SIKE

作者:Samuel Jaques,John M. Schanck

Abstract:We introduce models of computation that enable direct comparisons between classical and quantum algorithms. Incorporating previous work on quantum computation and error correction, we justify the use of the gate-count and depth-times-width cost metrics for quantum circuits. We demonstrate the relevance of these models to cryptanalysis by revisiting, and increasing, the security estimates for the Supersingular Isogeny Diffie–Hellman (SIDH) and Supersingular Isogeny Key Encapsulation (SIKE) schemes. Our models, analyses, and physical justifications have applications to a number of memory intensive quantum algorithms.

Title:Fully Secure Attribute-Based Encryption for t-CNF from LWE

作者:Rotem Tsabary

Abstract:Attribute-based Encryption (ABE), first introduced by [SW05,GPSW06], is a public key encryption system that can support multiple users with varying decryption permissions. One of the main properties of such schemes is the supported function class of policies. While there are fully secure constructions from bilinear maps for a fairly large class of policies, the situation with lattice-based constructions is less satisfactory and many efforts were made to close this gap. Prior to this work the only known fully secure lattice construction was for the class of point functions (also known as IBE).

In this work we construct for the first time a lattice-based (ciphertext-policy) ABE scheme for the function class?t-CNF, which consists of CNF formulas where each clause depends on at most t bits of the input, for any constant?t. This class includes NP-verification policies, bit-fixing policies and t-threshold policies. Towards this goal we also construct a fully secure single-key constrained PRF from OWF for the same function class, which might be of independent interest.

本届会议,除了精彩的论文汇报,还有学术大咖带来的讲座。本次会议共有两个特邀讲座,演讲者分别是来自康奈尔大学的Helen Nissenbaum 教授和来自马里兰大学的Jonathan Katz教授。小编也整理了两位学者的信息,不妨来了解一下。

Helen Nissenbaum


简介:Helen Nissenbaum是康奈尔理工学院和康奈尔大学信息科学系的教授。她的研究是从伦理的角度看待与信息技术、计算、数字媒体和数据科学相关的政策、法律、科学和工程。主题包括隐私、信任、责任感、安全性和技术设计中的价值观。她的书包括《困惑:隐私和抗议用户指南》、《隐私语境:技术、政策和社会生活的完整性》。

Jonathan Katz


简介:Jonathan Katz 1996年获得麻省理工学院数学和化学学士学位,随后于1998年获得哥伦比亚大学化学硕士学位。2002年获得哥伦比亚大学计算机科学博士学位。在研究生院期间,他在Telcordia Technologies(现在是ACS)担任研究科学家。他从2002年起就在马里兰大学教职。他曾在UCLA、IBM T.J.Watson研究中心和Ecole Normale Superieur担任访问职位。