Symmetric Primitives with Structured Secrets
Symmetric Primitives with Structured Secrets
复制标题
具有结构化秘密的对称原语
DOI：
10.1007/978-3-030-26948-7_23
复制
发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Sikhar Patranabis
中科院分区：
文献类型：
--
作者：
Navid Alamati;H. Montgomery;Sikhar Patranabis
对不可信方的加密数据进行保密管理是一个具有挑战性的问题，这激发了对各种各样的密码原语的研究。这类原语的一个特殊类别允许不受信任的一方使用一些不会泄露底层数据的辅助信息，将一个密钥下加密的密文转换为另一个密钥下的密文。对称设置中的这种原语的突出示例是密钥同态（弱）PRF、可更新加密和代理重新加密。尽管这些原语在它们的构造和安全要求方面显著不同，但是它们共享两个重要的属性：（a）它们具有具有结构或额外功能的秘密，以及（B）满足相当强的安全性定义的这些原语的所有已知构造都基于具体的公钥假设，例如，DDH和LWE。
Securely managing encrypted data on an untrusted party is a challenging problem that has motivated the study of a wide variety of cryptographic primitives. A special class of such primitives allows an untrusted party to transform a ciphertext encrypted under one key to a ciphertext under another key, using some auxiliary information that does not leak the underlying data. Prominent examples of such primitives in the symmetric setting are key-homomorphic (weak) PRFs, updatable encryption, and proxy re-encryption. Although these primitives differ significantly in terms of their constructions and security requirements, they share two important properties: (a) they have secrets with structure or extra functionality, and (b) all known constructions of these primitives satisfying reasonably strong definitions of security are based on concrete public-key assumptions, e.g., DDH and LWE.