International Association for Cryptologic Research

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22:47 [Job][New] Postdoc, Cryptographic Algorithms Group, CISPA, Saarland University, Germany

  The Cryptographic Algorithms Group is offering a 2-year post-doc position. We are part of the Center for IT-Security and Privacy (short: CISPA). The CISPA was founded in October 2011 as a competence center for IT security at Saarland University. It is a joint endeavor of Saarland University (UdS) and its on-site partner institutions: the Max Planck Institute for Informatics (MPI-INF), the Max Planck Institute for Software Systems (MPI-SWS), and the German Research Center for Artificial Intelligence (DFKI).

Requirements: A PhD in cryptography and related areas, excellence in research proven for example by publications in IACR conferences and workshops or venues like IEEE S&P, ACM CCS, NDSS, USENIX Security,…

Applicants interested in the positions should provide the following information in pdf format with the application:

- Research Statement

- CV

- List of publications, mark your top 2

- 2 reference letters

Expected starting date is Nov, 1st.

Cryptographic Algorithms Group:


22:47 [Job][New] Sr. SW Engineer – Security/Applied Cryptography Expert , Aspera - an IBM Company

  Aspera, an IBM Company is profitable, and headquartered in Emeryville, California with satellite offices in the United Kingdom, France and Singapore. Over 3,000 customers across all industries that need to move large volumes of data in industries such as enterprise IT, games and software development, government, legal & eDiscovery, life sciences, media & entertainment and oil & gas rely on Aspera software to move extreme data sets at high-speed over global distances.

• Focus on defining and building out security programs and quality programs

• Develop an analysis framework for vulnerabilities

• Code or help code the security framework components

• Develop patches and new security features to help mitigate security flaws

• Coordinate activities during the deployment of security-relevant features

• Perform security code audits and design reviews

• Architecture, design and coding of Aspera’s end-to-end security framework

• Threat and vulnerability analysis

• Code analysis, scanning

• Pen-test

• Ability to deliver results quickly and efficiently with iterative approache


• Strong software development background - C and C++, systems programming, web application frameworks, JavaScript

• Expert knowledge of applied cryptography and software security

• Ultra familiarity with common software security threats, CWE

• Expert knowledge of applied cryptography and software security

• Proven record - contribution or ownership of security framework design and implementation for large scale software systems

• Authentication and distributed authorization frameworks (SAML, OpenID, OAuth(2))

• Code analysis and scanning tools and processes

• Secure communication protocols, data protection, secure interaction with authentication and authorizations systems, and cloud services (particularly cloud storage)

• To

03:55 [News] Open Letter to the Hon'ble President of India


Open Letter to the Hon'ble President of India

The International Association of Cryptologic Research (IACR) is dismayed by reports of Professor Bimal Roy being dismissed in all but name as Director of the Indian Statistical Institute in Kolkata. Professor Roy has been a driving force in advancing the important field of cryptology in India, elevating its visibility to international level. Cryptology is a prime application of statistical and probabilistic methods.

The IACR confirms that Professor Roy deserves great recognition for his service to India and to the field of cryptology. He devoted his career to strengthening India's standing in this timely, fast advancing field. Removing him from this position one month before the appointment expires is an act that has put India in a shameful and awkward position in front of the international community of cryptology research and of mathematics in general.

The International Association of Cryptologic Research
June 21, 2015

18:17 [Pub][ePrint] How to Securely Prolong the Computational Bindingness of Pedersen Commitments, by Denise Demirel and Jean Lancrenon

  Pedersen commitments are important cryptographic primitives.

They allow a prover to commit to a certain value without revealing

any information about it and without the prover being able to change its mind later on. Since the first property holds unconditionally this is an essential primitive for many schemes providing long-term confidentiality. However, the second property only holds computationally. Hence, in the long run bindingness is lost, making the primitive improper for long-lived systems. Thus in this paper, we describe a protocol that, in a sense, prolongs the bindingness of a given Pedersen commitment. More precisely, we demonstrate how to prove in perfect zero-knowledge that a new Pedersen commitment - generated with a larger security parameter - and a corresponding old commitment both commit to the same value. We stress that this is a non-trivial procedure. Up until now the only known perfect zero-knowledge proof techniques for proving message equivalence of two commitments work when both commitments use isomorphic message spaces. However, as we will show in this work, to prolong the security of Pedersen commitments we cannot tolerate this restriction. Our prolonging technique works for non-isomorphic message spaces, is efficient, can be repeated an arbitrary number of times, maintains

unconditional confidentiality, and allows to preserve the format of

the Pedersen commitments. This makes the construction presented here

an important contribution to long-lived systems. Finally, we illustrate this by discussing how commitments with prolongable bindingness can be used to allow for archiving solutions that provide not only integrity but also confidentiality in the long-term.

18:17 [Pub][ePrint] SIMON and SPECK: Block Ciphers for the Internet of Things, by Ray Beaulieu and Douglas Shors and Jason Smith and Stefan Treatman-Clark and Bryan Weeks and Louis Wingers

  The U.S. National Security Agency (NSA) developed the SIMON and SPECK families of lightweight block ciphers as an aid for securing applications in very constrained environments where AES may not be suitable. This paper summarizes the algorithms, their design rationale, along with current cryptanalysis and implementation results.

18:17 [Pub][ePrint] SCLPV: Secure Certificateless Public Verification for Cloud Storage in Cyber-physical-social System, by Yuan Zhang and Chunxiang Xu and Shui Yu and Hongwei Li and Xiaojun Zhang

  Cyber-physical-social system (CPSS) allows individuals to share personal information collected from not only cyberspace, but also physical space. This has resulted in generating numerous data at a user\'s local storage. However, it is very expensive for users to store large data sets, and it also causes problems in data management. Therefore, it is of critical importance to outsource the data to cloud servers, which provides users an easy, cost-effective and flexible way to manage data. Whereas, users lose control on their data once outsourcing their data to cloud servers, which poses challenges on integrity of outsourced data. Many mechanisms have been proposed to allow a third-party auditor to verify data integrity using the public keys of users. Most of these mechanisms bear a strong assumption: the auditors are honest and reliable, and thereby are vulnerability in the case that auditors are malicious. Moreover, in most of these approaches, an auditor needs to manage users certificates to choose the correct public keys for verification.

In this paper, we propose a secure certificateless public integrity verification scheme (SCLPV). The SCLPV scheme is the first work that simultaneously supports certificateless public verification and resistance against malicious auditors to verify the integrity of outsourced data in CPSS. A formal and strict security proof proves the correctness and security of our scheme. In addition, an elaborate performance analysis demonstrates that our scheme is efficient and practical. Compared with the best of the existing certificateless public verification scheme (CLPV), the SCLPV provides stronger security guarantees in terms of remedying the security vulnerability of the CLPV and resistance against malicious auditors. At the same time, in comparison with the best of integrity verification scheme achieving resistance against malicious auditors, the communication cost between the auditor and the cloud server in the SCLPV is independent of the size of the processed data, meanwhile, the auditor in the SCLPV does not need to manage certificates.


  In remote authentication scheme, a remote user can communicate with server over open networks even though the physical distance is much far. Before interaction, they require to establish common session key by authenticating each other. Recently in 2014, Kumari et al. proposed the efficient scheme for remote user authentication. However in this paper, we show that the Kumari et al.\'s scheme is vulnerably susceptible to the Insider Attack, Stolen Verifier Attack, Session Key Disclosure Attack, Password Guessing Attack, Modification Attack, User Impersonation Attack, Replay Attack, Shoulder Surfing Attack and Denial of Service Attack. Afterwards, we have proposed an improved remote user authentication scheme to deal with these attacks and other attacks.

18:17 [Pub][ePrint] An analysis of the $C$ class of bent functions, by Bimal Mandal and Pantelimon Stanica and Sugata Gangopadhyay and Enes Pasalic

  Two (so-called $C, D$) classes of permutation-based bent Boolean functions were introduced by Carlet two decades ago, but without specifying some explicit construction methods for their construction (apart from the subclass $D_0$). In this article, we look in more detail at the $C$ class, and derive some existence and nonexistence results concerning the bent functions in the $C$ class for many of the known classes of permutations over $\\mathbb F_{2^n}$. Most importantly, the existence results induce generic methods of constructing bent functions in class $C$ which possibly do not belong to the completed Maiorana-McFarland class. The question whether the specific permutations and related subspaces we identify in this article indeed give bent functions outside the completed Maiorana-McFarland class remains open.

18:17 [Pub][ePrint] Generating S-Box Multivariate Quadratic Equation Systems And Estimating Algebraic Attack Resistance Aided By SageMath, by A.-M. Leventi-Peetz and J.-V. Peetz

  Methods are presented to derive with the aid of the computer mathematics

software system SageMath the Multivariate Quadratic equation systems (MQ) for the input and output bit variables of a cryptographic S-box starting from its algebraic expressions. Motivation to this work were the results of recent articles which we have verified and extended in an original way, to our knowledge, not yet published elsewhere. At the same time we present results contrary to the published ones which cast serious doubts on the suitability of previously presented formulas, supposed to quantify the resistance of S-boxes against algebraic attacks.

18:17 [Pub][ePrint] TriviA: A Fast and Secure Authenticated Encryption Scheme, by Avik Chakraborti, Anupam Chattopadhyay, Muhammad Hassan, Mridul Nandi

  In this paper, we propose a new hardware friendly authen- ticated encryption (AE) scheme TriviA based on (i) a stream cipher for generating keys for the ciphertext and the tag, and (ii) a pairwise in- dependent hash to compute the tag. We have adopted one of the ISO- standardized stream ciphers for lightweight cryptography, namely Triv- ium, to obtain our underlying stream cipher. This new stream cipher has a state that is a little larger than the state of Trivium to accommodate a 128-bit secret key and IV. Our pairwise independent hash is also an adaptation of the EHC or \"Encode-Hash-Combine\" hash, that requires the optimum number of field multiplications and hence requires small hardware footprint. We have implemented the design in synthesizable RTL. Pre-layout synthesis, using 65 nm standard cell technology under typical operating conditions, reveals that TriviA is able to achieve a high throughput of 91.2 Gbps for an area of 24.4 KGE. We prove that our construction has at least 128-bit security for privacy and 124-bit security of authenticity under the assumption that the underlying stream cipher produces a pseudorandom bit stream.