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19:17 [Pub][ePrint] PUF Modeling Attacks on Simulated and Silicon Data, by Ulrich Rührmair and Jan Sölter and Frank Sehnke and Xiaolin Xu and Ahmed Mahmoud and Vera Stoyanova and Gideon Dror and Jürgen Schmidhuber and

  We show in this paper how several proposed Strong

Physical Unclonable Functions (PUFs) can be broken by numerical

modeling attacks. Given a set of challenge-response pairs

(CRPs) of a Strong PUF, our attacks construct a computer

algorithm which behaves indistinguishably from the original PUF

on almost all CRPs. This algorithm can subsequently impersonate

the PUF, and can be cloned and distributed arbitrarily. This

breaks the security of almost all applications and protocols that

are based on the respective PUF.

The PUFs we attacked successfully include standard Arbiter

PUFs and Ring Oscillator PUFs of arbitrary sizes, and XOR

Arbiter PUFs, Lightweight Secure PUFs, and Feed-Forward

Arbiter PUFs of up to a given size and complexity. The attacks

are based upon various machine learning techniques, including

a specially tailored variant of Logistic Regression and Evolution


Our results were obtained on a large number of CRPs

coming from numerical simulations, as well as four million CRPs

collected from FPGAs and ASICs. The performance on silicon

CRPs is very close to simulated CRPs, confirming a conjecture

from earlier versions of this work. Our findings lead to new

design requirements for secure electrical PUFs, and will be useful

to PUF designers and attackers alike.

19:17 [Pub][ePrint] Compact Hardware Implementations of ChaCha, BLAKE, Threefish, and Skein on FPGA, by Nuray At and Jean-Luc Beuchat and Eiji Okamoto and Ismail San and Teppei Yamazaki

  The cryptographic hash functions BLAKE and Skein are built from the ChaCha stream cipher and the tweakable Threefish block cipher, respectively. Interestingly enough, they are based on the same arithmetic operations, and the same design philosophy allows one to design lightweight coprocessors for hashing and encryption. The key element of our approach is to take advantage of the parallelism of the algorithms to deeply pipeline our Arithmetic an Logic Units, and to avoid data dependencies by interleaving independent tasks. We show for instance that a fully autonomous implementation of BLAKE and ChaCha on a Xilinx Virtex-6 device occupies 144 slices and three memory blocks, and achieves competitive throughputs. In order to offer the same features, a coprocessor implementing Skein and Threefish requires a substantial higher slice count.

19:17 [Pub][ePrint] Public Key Exchange Using Matrices Over Group Rings, by Delaram Kahrobaei and Charalambos Koupparis and Vladimir Shpilrain

  We offer a public key exchange protocol in the spirit of Diffie-Hellman, but we use (small) matrices over a group ring of a (small) symmetric group as the platform. This ``nested structure\" of the platform makes computation very efficient for legitimate parties. We discuss security of this scheme by addressing the Decision Diffie-Hellman (DDH) and Computational Diffie-Hellman (CDH) problems for our platform.

19:17 [Pub][ePrint] A Conditional Proxy Broadcast Re-Encryption Scheme Supporting Timed-Release, by Kaitai Liang and Qiong Huang and Roman Schlegel and Duncan S. Wong and Chunming Tang

  To allow a delegator not only to delegate the keyword-controlled decryption rights of a broadcast encryption to a set of specified recipients, but also to control when the decryption rights will be delegated, in this paper, for the first time, we introduce a new notion called timed-release conditional proxy broadcast re-encryption (TR-CPBRE). We also propose a concrete construction for TR-CPBRE which can be proven selective identity adaptive CCA secure under the (P,Q,f)-GDDHE assumption, and chosen-time period chosen-ciphertext secure under the BDH assumption. When compared with the existing CPBRE and TR-PRE schemes, our scheme achieves better efficiency, and enables the delegator to make a fine-grained delegation of decryption rights to multiple delegatees.

19:17 [Pub][ePrint] The Algorithm of AAES, by Shiyong Zhang and Gongliang Chen and Lei Fan

  The Advanced Encryption Standard (AES) was specified in 2001 by the National Institute of Standards and Technology. This paper expand the method and make it possible to realize a new AES-like algorithm that has 256 bits fixed block size, which is named AAES algorithm. And we use Verilog to simulate the arithmetic and use Lattice Diamond to simulate the hardware property and action. We get the conclusion that the algorithm can be easily used on indestury and it is more robustness and safety than AES. And they are on the same order of magnitude in hardware implementation.

19:17 [Pub][ePrint] On r-th Root Extraction Algorithm in F_q For q=lr^s+1 (mod r^(s+1)) with 0 < l < r and Small s, by Namhun Koo and Gook Hwa Cho and Soonhak Kwon

  We present an r-th root extraction algorithm over a finite field

F_q. Our algorithm precomputes a primitive r^s-th root of unity where s is the largest positive integer satisfying r^s| q-1, and is applicable for the cases when s is small. The proposed algorithm requires one exponentiation for the r-th root computation and is favorably compared to the existing algorithms.

06:57 [Event][New] Central European Conference on Cryptology 2013

  Submission: 15 April 2013
Notification: 29 April 2013
From June 26 to June 28
Location: Telc, Czech Republic
More Information:

06:56 [Event][New] ECC 2013: 17th Workshop on Elliptic Curve Cryptography

  From September 16 to September 18
Location: Leuven, Belgium
More Information:

16:56 [Event][New] SPE2013: IEEE 2013 Third International Workshop on Security and Privacy Engineering

  Submission: 15 March 2013
Notification: 4 April 2013
From June 27 to July 2
Location: Santa Clara, CA, USA
More Information:

16:55 [Event][New] VizSec 2013: 10th International Symposium on Visualization for Cyber Security

  Submission: 8 July 2013
Notification: 16 August 2013
From October 14 to October 14
Location: Atlanta, GA, United States
More Information:

18:32 [Job][New] Post-Doc, Aalto University School of Science, Helsinki, Finland

  The cryptography group at Aalto University School of Science is specialized in statistical cryptanalysis of symmetric-key cryptographic primitives as well as implementation efficiency and security of both asymmetric-key and symmetric-key primitives. Also mathematical structures that provide resistance against such attacks belong to the group´s interest areas. In the current call we look for researchers who have PhD degree and background in the areas mentioned above.