IACR News
Here you can see all recent updates to the IACR webpage. These updates are also available:
06 September 2017
Ritam Bhaumik, Mridul Nandi
ePrint ReportIn this paper we show an improved bound for integrity of OCB3 in terms of the number of blocks in the forging attempt. In particular we show that when the number of encryption query blocks is not more than birthdaybound (an assumption without which the privacy guarantee of OCB3 disappears), even an adversary making forging attempts with the number of blocks in the order of 2n=L_MAX (n being the block-size and L_MAX being the length of the longest block) may fail to break the integrity of OCB3.
David Bruce Cousins, Giovanni Di Crescenzo, Kamil Doruk G\"{u}r, Kevin King, Yuriy Polyakov, Kurt Rohloff, Gerard W. Ryan, Erkay Sava\c{s}
ePrint ReportOur work is the first implementation of non-trivial program obfuscation based on polynomial rings. Our contributions include multiple design and implementation advances resulting in reduced program size, obfuscation runtime, and evaluation runtime by many orders of magnitude. We implement our design in software and experimentally assess performance in a commercially available multi-core computing environment. Our implementation achieves runtimes of 6.7 hours to securely obfuscate a 64-bit conjunction program and 2.5 seconds to evaluate this program over an arbitrary input. We are also able to obfuscate a 32-bit conjunction program with 48 bits of security in 7 minutes and evaluate the obfuscated program in 43 milliseconds on a commodity desktop computer, which implies that 32-bit conjunction obfuscation is already practical. Our graph-induced (directed) encoding implementation runs up to 25 levels, which is higher than previously reported in the literature for this encoding. Our design and implementation advances are applicable to obfuscating more general compute-and-compare programs and can also be used for many cryptographic schemes based on lattice trapdoors.
Federico Giacon, Eike Kiltz, Bertram Poettering
ePrint ReportWe then switch to the constructive side by (d) introducing the concept of an augmented data encapsulation mechanism (ADEM) that promises robustness against multi-instance attacks, (e) proposing a variant of hybrid encryption that uses an ADEM instead of a DEM to alleviate the problems of the standard KEM+DEM composition, and (f) constructing practical ADEMs that are secure in the multi-instance setting.
Darren Hurley-Smith, Julio Hernandez-Castro
ePrint ReportYu Long Chen, Atul Luykx, Bart Mennink, Bart Preneel
ePrint ReportFast Scalar Multiplication for Elliptic Curves over Binary Fields by Efficiently Computable Formulas
Saud Al Musa, Guangwu Xu
ePrint ReportJing Li, Licheng Wang
ePrint ReportOur solution is comprised of three steps. First, Ostrovsky and Skeith's idea for building FHE from a multiplicative homomorphic encryption (MHE) over a non-abelian simple group is extended so that FHE can be built from an MHE over a group ring that takes an underlying non-abelian simple group as the natural embedding. Second, non-trivial zero factors of the underlying ring are plugged into the encoding process for entirely removing the noise after fully homomorphic operations, and a slight but significant modification towards Ostrovsky-Skeith's NAND gate representation is also introduced for avoiding computing inverse matrices of the underlying group ring. In such manner, a symmetric FHE scheme is produced. Finally, based on the proposed symmetric FHE scheme, an asymmetric FHE scheme is built by taking a similar diagram to the well-known GM84 scheme. But different from GM84 that only supports ciphertext homomorphism according to the logically incomplete gate XOR, our scheme supports ciphertext homomorphism according to the logically complete gate NAND.
05 September 2017
Eurocrypt
04 September 2017
STMicroelectronics, Agrate Brianza, Italy (close to Milan)
Job PostingYour mission will be to:
- Deploy security expertise and help ST product divisions shape the right security solutions for their products (ICs).
- Develop cryptographic and security software IPs.
- Stay on top of security needs and state-of-the-art evolution, anticipating/identifying solutions and partners, developing or making available the security competences and IPs that will be needed by the Company in a 3-5 years time frame.
The candidate should have:
- Software development skills (in particular C). Experience on embedded devices (i.e. microcontrollers) is particularly appreciated
- A theoretical background in cryptography (symmetric and asymmetric) and side-channel attacks
- Teamwork, networking, customer-orientation & communication skills
- Motivation for bridging research outcomes and product design
Closing date for applications: 30 November 2017
Contact: Ruggero Susella - ruggero.susella (at) st.com
University of Tartu
Job PostingWe are starting a project in which we will develop methods for the verification of proofs in quantum cryptography. Similar to what the EasyCrypt tool does in classical cryptography. The scope of the project covers everything from the logical foundations, through the development of tools, to the verification of real quantum protocols.
The ideal candidate would have experience in one or more of the following topics:
- Semantics
- Theorem proving
- Verification of classical cryptography
- Quantum cryptography
- Quantum computation / communication
Students who are enthusiastic about those topics, and have some background related to (some) of these, are encouraged to apply.
Please contact Dominique Unruh (unruh (at) ut.ee) if you have more questions about the project, the required background, Estonia, the position itself, or the application process.
PhD students will have to pay no tuition fees and will be funded with 1000 Euro net (after taxes). This is highly competitive in Estonia due to low costs of living. Healthcare is covered.
To apply, please send the following documents to unruh (at) ut.ee:
- Curriculum vitae (please explain your scientific background)
- List of publications
- Research plan (i.e., how do you think you could contribute to the topic)
- At least two letters of reference (please ask for the letters to be sent directly to us)
- Masters degree (if you do not have it yet, provide whatever confirmation you can get)
- Grade transcript
Applications will be accepted until the position is filled.
Closing date for applications:
Contact: Dominique Unruh (unruh (at) ut.ee)
More information: http://crypto.cs.ut.ee/Main/PhdInVerificationOfQuantumCryptography
University of Tartu
Job PostingWe are starting a project in which we will develop methods for the verification of proofs in quantum cryptography. Similar to what the EasyCrypt tool does in classical cryptography. The scope of the project covers everything from the logical foundations, through the development of tools, to the verification of real quantum protocols.
The ideal candidate would have experience in:
- Semantics
- Theorem proving
- Verification of classical cryptography
- Quantum cryptography
- Quantum computation / communication
Of course, expertise in all those areas is very rare, so candidates who are strong in some of those areas and are interested in the others are encouraged to apply!
Please contact Dominique Unruh (unruh (at) ut.ee) if you have more questions about the project, the required background, Estonia, the position itself, or the application process.
The salary range is 30000-36000 Euro per year (depending on experience), which is highly competitive in Estonia due to low costs of living and low income tax rate (20%), pension contributions and health insurance are covered by the employer.
The position is for three years, as soon as possible till August 31, 2020. The starting date and duration can be negotiated (in both directions).
To apply, please send the following documents to unruh (at) ut.ee:
- Curriculum vitae (please explain your scientific background)
- List of publications
- Research plan (i.e., how do you think you could contribute to the topic)
- At least two letters of reference (please ask for the letters to be sent directly to us)
- Phd degree
Applications will be accepted until the position is filled.
Closing date for applications:
Contact: Dominique Unruh
More information: http://crypto.cs.ut.ee/Main/PostdocInVerificationOfQuantumCryptography
03 September 2017
St. Moritz, Switzerland, 17 January - 19 January 2018
Event CalendarSubmission deadline: 1 January 2018
01 September 2017
Jiang Zhang, Yu Yu
ePrint Report31 August 2017
Avijit Dutta, Ashwin Jha, Mridul Nandi
ePrint ReportYin Li, Xingpo Ma, Qin Chen, Chuanda Qi
ePrint ReportStephen D. Miller, Bhargav Narayanan, Ramarathnam Venkatesan
ePrint ReportDaniel Masny
ePrint ReportSteven Myers, Adam Shull
ePrint ReportBeyond the construction, we introduce new security definitions for the problem at hand, prove our construction secure, discuss use cases, and provide quantitative data showing its practical benefits and efficiency. We show the construction extends to identity-based proxy re-encryption and revocable-storage attribute-based encryption, and thus that the construction is robust, supporting most primitives of interest.
Lorenzo Grassi
ePrint ReportEven if such a 5-round distinguisher has higher complexity than the one present in the literature, it allows to set up the first key-recovery attack on 6-round AES that exploits directly a 5-round secret-key distinguisher. The goal of this paper is indeed to present and explore new approaches, showing that even a distinguisher like the one presented at Eurocrypt - believed to be hard to exploit - can be used to set up a key-recovery attack. Finally we show how to exploit the proposed 4-round distinguisher to set up new (practically verified) key-recovery attacks on 5-round AES with a single secret S-Box.