International Association for Cryptologic Research

# IACR News Central

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2015-01-12
10:17 [Pub][ePrint]

Lattice rounding in Euclidean space can be viewed as finding the nearest point in the orbit of an action by a discrete group, relative to the norm inherited from the ambient space. Using this point of view, we initiate the study of non-abelian analogs of lattice rounding involving matrix groups. In one direction, we give an algorithm for solving a normed word problem when the inputs are random products over a basis set, and give theoretical justification for its success. In another direction, we prove a general inapproximability result which essentially rules out strong approximation algorithms (i.e., whose approximation factors depend only on dimension) analogous to LLL in the general case.

09:21 [Event][New]

Submission: 10 July 2015
From November 2 to November 5
Location: Algiers, Algeria

2015-01-10
22:17 [Forum]

See the following link for the Nit-Picking PLAID response to this Paper https://dl.dropboxusercontent.com/u/41736374/UnpickingReport%20V1.pdf From: 2014-27-11 22:00:58 (UTC)

22:17 [Forum]

On behalf of the "Unpicking PLAID" research team, I would like to point out that our response to this report is available from: http://www.cryptoplexity.informatik.tu-darmstadt.de/media/crypt/pdf/plaid-editorreport-response.pdf This response expresses our viewpoint on that report, rectifying some misrepresented facts and countering false allegations. In particular (but not limited to): 1) The author(s) of the report seem to consistently confuse the mere lack of known attacks with a proof of security. 2) They argue about a lack of a formal definition of privacy in our work and digress into musing about an Oxford dictionary definition of privacy. Our paper, however, allows the reader to easily infer what our attacks against the ISO standard achieve: tracing cards across executions, and identifying the supported key set of a card. None of these attacks should be possible according to PLAID\'s own claims of privacy. 3) They try to minimise the impact of our attacks, based on the availability of CPLC data, implying that CPLC data is anyway always available even in privacy-sensitive scenarios - which is incorrect. Furthermore, they completely ignore our fingerprinting attack on key sets, and focus only on the RSA fingerprinting attack. 4) They credit us for claims which we never made, and misrepresent the timeline and references in our paper. Finally, we wish to remark that the personal email correspondence with Professors Fischlin and Paterson, linked to in Annex A of the project editor\'s report, was published without their consent. We consider the situation to be self-explanatory, and encourage readers to draw their own conclusions. Sincerely, The "Unpicking PLAID" team. From: 2015-08-01 09:52:28 (UTC)

00:14 [Job][New]

• School of Computer Science and Software Engineering

• Full Time, Fixed Term (3 year) Appointment

• Level B

• Ref No: 25277

The School is one of leading computing schools in Australia. It conducts research in a number of thematic areas including Intelligent Systems, Software Engineering, Computer and Information Security, Visual Information Processing and Multimedia Content Management.

The School of Computer Science and Software Engineering is one of seven Schools with the Faculty of Engineering and Information Sciences. It delivers a full range of quality courses, both onshore and offshore (Dubai, Singapore, Malaysia), ranging from undergraduate Bachelor’s degrees, through Coursework and Research Masters to PhD.

This position will teach and coordinate subjects in the School at undergraduate and postgraduate level; contribute to the research in information security and cryptography and supervise research students. You will work closely with the Head of School and other staff on the introduction, revision and maintenance of undergraduate and postgraduate subjects.

To apply for this position you will need to address the selection criteria as part of your application which is located within the position description below.

Apply online: http://uow.employment.com.au/jobs/Lecturer/1635

2015-01-08
11:48 [Event][New]

Submission: 4 April 2015
From September 23 to September 25
Location: Vienna, Austria

10:17 [Forum]

On behalf of the "Unpicking PLAID" research team, I would like to point out that our response to this report is available from: http://www.cryptoplexity.informatik.tu-darmstadt.de/media/crypt/pdf/plaid-editorreport-response.pdf This response expresses our viewpoint on that report, rectifying some misrepresented facts and countering false allegations. In particular (but not limited to): 1) The author(s) of the report seem to consistently confuse the mere lack of known attacks with a proof of security. 2) They argue about a lack of a formal definition of privacy in our work and digress into musing about an Oxford dictionary definition of privacy. Our paper, however, allows the reader to easily infer what our attacks against the ISO standard achieve: tracing cards across executions, and identifying the supported key set of a card. None of these attacks should be possible according to PLAID\'s own claims of privacy. 3) They try to minimise the impact of our attacks, based on the availability of CPLC data, implying that CPLC data is anyway always available even in privacy-sensitive scenarios - which is incorrect. Furthermore, they completely ignore our fingerprinting attack on key sets, and focus only on the RSA fingerprinting attack. 4) They credit us for claims which we never made, and misrepresent the timeline and references in our paper. Finally, we wish to remark that the personal email correspondence with Professors Fischlin and Paterson, linked to in Annex A of the project editor\'s report, was published without their consent. We consider the situation to be self-explanatory, and encourage readers to draw their own conclusions. Sincerely, The "Unpicking PLAID" team. From: 2015-08-01 09:52:28 (UTC)

10:17 [Pub][ePrint]

Embedded microcontroller applications often experience multiple limiting constraints: memory, speed, and for a wide range of portable devices, power. Applications requiring encrypted data must simultaneously optimize the block cipher algorithm and implementation choice against these limitations. To this end we investigate block cipher implementations that are optimized for speed and energy efficiency, the primary metrics of devices such as the MSP430 where constrained memory resources nevertheless allow a range of implementation choices. The results set speed and energy efficiency records for the MSP430 device at 132 cycles/byte and 2.18 uJ/block for AES-128 and 103 cycles/byte and 1.44 uJ/block for equivalent block and key sizes using the lightweight block cipher SPECK. We provide a comprehensive analysis of size, speed, and energy consumption for 24 different variations of AES and 20 different variations of SPECK, to aid system designers of microcontroller platforms optimize the memory and energy usage of secure applications.

05:52 [Event][New]

Submission: 17 June 2015
From November 24 to November 26
Location: Kanazawa, Japan

2015-01-07
10:17 [Pub][ePrint]

Password Hashing, a technique commonly implemented by a server to protect passwords of clients, by performing a one-way transformation on the password, turning it into another string called the hashed password. In this paper, we introduce a secure password hashing framework Rig which is based on secure cryptographic hash functions. It provides the flexibility to choose different functions for different phases of the construction. The design of the scheme is very simple to implement in software and is flexible as the memory parameter is independent of time parameter (no actual time and memory trade-o) and is strictly sequential (difficult to parallelize) with comparatively huge memory consumption that provides strong resistance against attackers using multiple processing units. It supports client-independent updates, i.e., the server can increase the security parameters by updating the existing password hashes without knowing the password. Rig can also support the server relief protocol where the client bears the maximum effort to compute the password hash, while there is minimal effort at the server side. We analyze Rig and show that our proposal provides an exponential time complexity against the low-memory attack.

10:17 [Pub][ePrint]

We study simulation-based, selective opening security against chosen-ciphertext attacks (SIM-SO-CCA security) for public key encryption (PKE). In a selective opening, chosen-ciphertext attack (SO-CCA), an adversary has access to a decryption oracle, sees a vector of ciphertexts, adaptively chooses to open some of them, and obtains the corresponding plaintexts and random coins used in the creation of the ciphertexts. The SIM-SO-CCA notion captures the security of unopened ciphertexts with respect to probabilistic polynomial-time (ppt) SO-CCA adversaries in a semantic way: what a ppt SO-CCA adversary can compute can also be simulated by a ppt simulator with access only to the opened messages. Building on techniques used to achieve weak deniable encryption and non-committing encryption, Fehr \\emph{et al.} (Eurocrypt 2010) presented an approach to constructing SIM-SO-CCA secure PKE from extended hash proof systems (EHPSs), collision-resistant hash functions and an information-theoretic primitive called Cross Authentication Codes (XACs). We generalize their approach by introducing a special type of Key Encapsulation Mechanism (KEM) and using it to build SIM-SO-CCA secure PKE. We investigate what properties are needed from the KEM to achieve SIM-SO-CCA security. We also give three instantiations of our construction. The first uses hash proof systems, the second relies on the $\\nnn$-Linear assumption, and the third uses indistinguishability obfuscation (iO) in combination with extracting, puncturable Pseudo-Random Functions in a similar way to Sahai and Waters (STOC 2014). Our results establish the existence of SIM-SO-CCA secure PKE assuming only the existence of one-way functions and iO. This result further highlights the simplicity and power of iO in constructing different cryptographic primitives.