Trusted Computing using Enhanced Manycore Architectures with Cryptoprocessors

International audienceManycore architectures correspond to a main evolution of computing systems due to their high processing power. Many applications can be executed in parallel which provides users with a very efficient technology. Cloud computing is one of the many domains where manycore architectures will play a major role. Thus, building secure manycore architectures is a critical issue. However a trusted platform based on manycore architectures is not available yet. In this paper we discuss the main challenges and some possible solutions to enhance manycore architectures with cryptoprocessor

Tweakable HCTR: A BBB Secure Tweakable Enciphering Scheme

\textsf{HCTR}, proposed by Wang et al., is one of the most efficient candidates of tweakable enciphering schemes that turns an $n$-bit block cipher into a variable input length tweakable block cipher. Wang et al. have shown that \textsf{HCTR} offers a cubic security bound against all adaptive chosen plaintext and chosen ciphertext adversaries. Later in FSE 2008, Chakraborty and Nandi have improved its bound to $O(\sigma^2 / 2^n)$, where $\sigma$ is the total number of blocks queried and $n$ is the block size of the block cipher. In this paper, we propose \textbf{tweakable \textsf{HCTR}} that turns an $n$-bit tweakable block cipher to a variable input length tweakable block cipher by replacing all the block cipher calls of \textsf{HCTR} with tweakable block cipher. We show that when there is no repetition of the tweak, tweakable \textsf{HCTR} enjoys the optimal security against all adaptive chosen plaintext and chosen ciphertext adversaries. However, if the repetition of the tweak is limited, then the security of the construction remains close to the security bound in no repetition of the tweak case. Hence, it gives a graceful security degradation with the maximum number of repetition of tweaks

Pipeline Implementation of Three Authenticated Encryption Algorithms

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Hardware implementation of some ECB-Mix-ECB based algorithms

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STES: A Stream Cipher Based Low Cost Scheme for Securing Stored Data

International audienceThe problem of securing data present on USB memories and SD cards has not been adequately addressed in thecryptography literature. While the formal notion of a tweakable enciphering scheme (TES) is well accepted as the proper primitive forsecure data storage, the real challenge is to design a low cost TES which can perform at the data rates of the targeted memory devices.In this work, we provide the first answer to this problem. Our solution, called STES, combines a stream cipher with a XOR universalhash function. The security of STES is rigorously analyzed in the usual manner of provable security approach. By carefully definingappropriate variants of the multi-linear hash function and the pseudo-dot product based hash function we obtain controllable trade-offsbetween area and throughput. We combine the hash function with the recent hardware oriented stream ciphers, namely Mickey, Grainand Trivium. Our implementations are targeted towards two low cost FPGAs—Xilinx Spartan 3 and Lattice ICE40. Simulation resultsdemonstrate that the speeds of encryption/decryption match the data rates of different USB and SD memories. We believe that ourwork opens up the possibility of actually putting FPGAs within controllers of such memories to perform low-level in-place encryption

ELmD: A Pipelineable Authenticated Encryption and Its Hardware Implementation

International audienceAuthenticated encryption schemes which resist misuse of nonce at some desired level of privacy are two-pass or Macthen- Encrypt constructions (inherently inefficient but provide full privacy) and online constructions like McOE, sponge-type authenticated encryptions (such as duplex) and COPA. Only the last one is almost parallelizable except that for associated data processing, the final block-cipher call is sequential (it needs to wait for the encryption of all the previous ones). In this paper, we design a new online secure authenticated encryption, called ELmD or Encrypt-Linear mix-Decrypt, which is completely (two-stage) parallel (even in associated data) and fully pipeline implementable. It also provides full privacy when associated data is not repeated. Like COPA, our construction is based on EME, an Encrypt-Mix-Encrypt type SPRP construction (secure against chosen plaintext and ciphertext). But unlike EME, we have used an online computable efficient linear mixing instead of a non-linear mixing. We have also provided the hardware implementation of the construction and compare the performance with similar constructions like COPA and EME2

Halo-spot and external stem necrosis of tomato caused by Pseudomonas syringae in Sinaloa, Mexico

Pseudomonas syringae pv. tomato has been observed in the fields in Sinaloa causing typical symptoms of bacterial speck. During the 2004–2005 growing seasons atypical symptoms were observed in tomato varieties grown in Sinaloa, consisting of external necrosis of stems, petioles, peduncles and fruit calyxes. Although the disease affected 80–90% of the foliage, there were no speck symptoms on fruit. The objectives of this study were to: (a) identify the causal agent of the disease, (b) determine the sensitivity of the pathogen to various antibiotics in vitro and (c) test their efficacy for controlling the disease in tomato plants under greenhouse conditions. The results of the present study indicate that biochemical and physiological characteristics as well as the molecular studies of bacterial isolates associated with the yellow halo spot and external necrosis of the stem of tomato are closely related to P. syringae pv. tomato, although whether these isolates indeed belong to pathovar tomato needs further assessment. The efficacy of gentamicin sulfate and oxytetracycline chlorhydrate in vitro, and in planta under greenhouse conditions, represents a possible option for the chemical control of the disease under field conditions. The results also indicate a reduced sensitivity of the characterized isolates to copper hydroxide as compared with the above mentioned antibiotics in northern Sinaloa

Impact of an exercise program on acylcarnitines in obesity: a prospective controlled study

<p>Abstract</p> <p>Background</p> <p>Acylcarnitine (AC) transport dysfunction into the mitochondrial matrix is one of the pathophysiological mechanisms of type 2 diabetes mellitus (DM). The effect of an aerobic exercise (AE) program on this condition in obese subjects without DM is unclear.</p> <p>Methods</p> <p>A prospective, randomized, longitudinal, interventional study in a University Research Center involved a 10-week AE program in 32 women without DM and a body mass index (BMI) greater than 27 kg/m². (Cases n = 17; Controls n = 15). The primary objective was to evaluate the influence of a controlled AE program on beta-oxidation according to modifications in short, medium, and long-chain ACs. Secondary objectives were to define the behavior of amino acids, and the correlation between these modifications with metabolic and anthropometric markers.</p> <p>Results</p> <p>The proportion of dropouts was 17% and 6% in controls and cases, respectively. In cases there was a significant reduction in total carnitine (30.40 [95% CI 28.2 to 35.6]) vs. (29.4 [CI 95% 25.1 to 31.7]) <it>p =</it> 0.0008 and long-chain AC C14 (0.06 [95% CI 0.05 to 0.08]) vs. (0.05 [95% CI 0.05 to 0.09]) <it>p =</it> 0.005 and in C18 (0.31 [95% CI 0.27 to 0.45]) vs. (0.28 [95% CI 0.22 to 0.32]) <it>p =</it> 0.03. Free fatty acid levels remained without change during the study in both groups.</p> <p>Conclusion</p> <p>In conclusion, a controlled 10-week AE program improved beta-oxidation by reducing long-chain ACs. This finding highlights the importance that AE might have in avoiding or reverting lipotoxicity, and in consequence, improving insulin sensitivity and pancreatic beta cell functional reserve.</p