Constant Size Ciphertexts in Threshold Attribute-Based Encryption
Constant Size Ciphertexts in Threshold Attribute-Based Encryption
复制标题
DOI：
10.1007/978-3-642-13013-7_2
复制
发表时间：
2010-05
期刊：
影响因子：
--
通讯作者：
Javier Herranz;Fabien Laguillaumie;Carla Ràfols
中科院分区：
文献类型：
--
作者：
Javier Herranz;Fabien Laguillaumie;Carla Ràfols
基于属性的密码学是最近几年出现的一种很有前途的数字安全原始技术。例如，它为匿名访问控制问题提供了很好的解决方案。在基于密文策略的属性加密方案中，用户的密钥依赖于他们的属性。当加密消息时，发送者选择接收者必须持有哪些属性子集才能解密。所有当前允许合理表达的解密策略的基于属性的加密方案产生密文，其大小至少线性地依赖于策略中所涉及的属性的数量。在本文中，我们提出了密文大小恒定的第一个方案。我们的方案适用于门限情况：被授权解密的用户是那些在特定的属性宇宙中至少持有由发送者选择的某个门限的属性的用户。可以对加权门限解密策略的情况进行扩展。该方案对选择性选择明文攻击的安全性可以在标准模型下通过归结为增广多指数序列决策Diffie-Hellman(AMSE-DDH)问题来证明。
Attribute-based cryptography has emerged in the last years as a promising primitive for digital security. For instance, it provides good solutions to the problem of anonymous access control. In a ciphertext-policy attribute-based encryption scheme, the secret keys of the users depend on their attributes. When encrypting a message, the sender chooses which subset of attributes must be held by a receiver in order to be able to decrypt.All current attribute-based encryption schemes that admit reasonably expressive decryption policies produce ciphertexts whose size depends at least linearly on the number of attributes involved in the policy. In this paper we propose the first scheme whose ciphertexts have constant size. Our scheme works for the threshold case: users authorized to decrypt are those who hold at leasttattributes among a certain universe of attributes, for some thresholdtchosen by the sender. An extension to the case of weighted threshold decryption policies is possible. The security of the scheme against selective chosen plaintext attacks can be proven in the standard model by reduction to the augmented multi-sequence of exponents decisional Diffie-Hellman (aMSE-DDH) problem.