Danping Shi

High‐resolution electron microscopic study of the interface between diamond film and its substrate

A high‐resolution electron microscopic (HREM) study of the interface structure between diamond film and its silicon substrate has been carried out. The HREM images reveal that there is an amorphous layer between diamond film and its substrate for a sample grown by the hot filament chemical vapor deposition. β‐SiC crystallites are embedded in this amorphous layer. The HREM images of cross‐sectional specimens reveal that the diamond crystallites can nucleate directly on either the intermediate amorphous layer, the β‐SiC crystallites, or at some scratches of the Si substrate.

Match Box Meet-in-the-Middle Attacks on the SIMON Family of Block Ciphers

SIMON is a family of lightweight block ciphers designed by the U.S National Security Agency in 2013. In this paper, we analyze the resistance of the SIMON family of block ciphers against the recent match box meet-in-the-middle attack which was proposed in FSE 2014. Our attack particularly exploits the weaknesses of the linear key schedules of SIMON. Since the data available to the adversary is rather limited in many concrete applications, it is worthwhile to assess the security of SIMON against such low-data attacks.

Improved Linear (hull) Cryptanalysis of Round-reduced Versions of SIMON

摘要创新点密码算法的不同部件具有相同输入时的线性逼近的相关度计算不能应用堆积引理, 其计算是一个对线性分析结果有重要影响的难题。 充分考虑了 SIMON 分组密码算法不同运算的相关性, 通过化标准二次型的方法准确计算了轮函数线性逼近的相关度, 得到精确的线性分析结果。 基于混合整数线性规划建模, 找到了 SIMON 算法的多个版本的更好的线性迹和线性闭包, 给出了 SIMON 的更好的密钥恢复攻击结果。

Error-Tolerant Algebraic Side-Channel Attacks Using BEE

Algebraic side-channel attacks are a type of side-channel analysis which can recover the secret information with a small number of samples e.g., power traces. However, this type of side-channel analysis is sensitive to measurement errors which may make the attacks fail. In this paper, we propose a new method of algebraic side-channel attacks which considers noisy leakages as integers restricted to intervals and finds out the secret information with the help of a constraint programming compiler named BEE. To demonstrate the efficiency of this new method in algebraic side-channel attacks, we analyze some popular implementations of block ciphers--PRESENT, AES, and SIMON under the Hamming weight or Hamming distance leakage model. For AES, our method requires the least leakages compared with existing works under the same error model. For both PRESENT and SIMON, we provide the first analytical results of them under algebraic side-channel attacks in the presence of errors. To further demonstrate the wide applicability of this new method, we also extend it to cold boot attacks. In the cold boot attacks against AES, our method increases the success rate by over

Enhanced exchange bias in IrMn/CoFe deposited on self-organized hexagonally patterned nanodots

25\,\%

On the Complexity of Impossible Differential Cryptanalysis

25% than previous works.

Programming the Demirci-Selçuk Meet-in-the-Middle Attack with Constraints

One-dimensional core-shell nanostructures consisting of a ferromagnetic cobalt core and a multiferroic BiFeO3 (BFO) shell were fabricated by an artificial two-step methodology. The coupling between the ferromagnetic core and multiferroic shell manifests a significant exchange bias effect which gives a clear demonstration of the anti-ferromagnetic functionality of the BFO shell material. Exchange biases of 30 Oe and 60 Oe are observed at 300 K and at 5 K, respectively. Superparamagnetic contributions at lower temperatures play an important role in contributing to overall magnetic behavior. Dominant shape anisotropy causes parallel alignment of the easy magnetization axis along the axis of core-shell nanowires. A coherent mode of the magnetization reversal mechanism is observed by the angular dependence of coercivity (H c). This versatile two-step methodology can be employed to fabricate and investigate many other hybrid nanostructures leading to a vast scope of investigation for researchers.

Linear(hull) Cryptanalysis of Round-reduced Versions of KATAN

Exchange biased nanostructures of IrMn/CoFe were deposited on anodized alumina with hexagonally patterned nanodot surface structures. Nanodots with diameters of 20, 70, and 100 nm were fabricated to investigate the size effect on the magnetic properties. Magnetometry and the first-order reversal curve method revealed significant enhancements of the exchange bias and coercivity in the nanodots compared with flat films. The enhancements can be attributed to the effective reduction of ferromagnet domain sizes and increased random fields due to the nanostructure morphology and domain wall pinning by the boundaries between adjacent nanodots.