Defending Against Key Exfiltration: Efficiency Improvements for Big-Key Cryptography via Large-Alphabet Subkey Prediction
Defending Against Key Exfiltration: Efficiency Improvements for Big-Key Cryptography via Large-Alphabet Subkey Prediction
复制标题
防御密钥泄露：通过大字母子密钥预测提高大密钥密码学的效率
DOI：
10.1145/3133956.3133965
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Dai, Wei
中科院分区：
文献类型：
--
作者：
Bellare, Mihir;Dai, Wei
为了推进使用大密钥作为对密钥泄漏的实际防御，本文提供了有界检索模型（BRM）中的密码方案的效率改进。我们确定探测复杂性（方案访问存储大密钥的慢存储介质的数量）作为主要成本。我们的主要技术贡献是我们所谓的大字母表子键预测引理。它给出了在大密钥的块的随机序列的泄漏下的可预测性的良好界限，作为块大小的函数。我们使用它来显着降低达到给定安全级别所需的探测复杂性。与其他技术一起，这产生了BRM对称加密方案和BRM公钥识别方案的安全保护性能改进。
Towards advancing the use of big keys as a practical defense against key exfiltration, this paper provides efficiency improvements for cryptographic schemes in the bounded retrieval model (BRM). We identify probe complexity (the number of scheme accesses to the slow storage medium storing the big key) as the dominant cost. Our main technical contribution is what we call the large-alphabet subkey prediction lemma. It gives good bounds on the predictability under leakage of a random sequence of blocks of the big key, as a function of the block size. We use it to significantly reduce the probe complexity required to attain a given level of security. Together with other techniques, this yields security-preserving performance improvements for BRM symmetric encryption schemes and BRM public-key identification schemes.