我们构建了除已验证通信外不需要信任的基础设施以及满足有关在通用组成下（假设只存在增强的陷门排列）受保护的安全性的有意义概念的首次安全计算协议。安全性概念与Prabhakaran和Sahai“angel-based”框架（ STOC'04 ）的广泛化相契合并表明了超多项式时间模拟安全性。目前已知这种安全概念只有在有力具体的硬度假设中才可得到实现。我们建设中的关键因素之一即是满足安全性有力新概念的承诺方案。针对所选承诺攻击（CCA安全）的安全性，这一概念意为即使攻击者能够访问能给对手提供解除承诺信息来承诺对手的选择的提取指引，安全性仍然能够得到保证。这一概念强于并发型非可塑性且利益独立。我们构造了基于标准单向函数且不含信任设置的CCA安全承诺。据我们所知，通过使用不需受信任的设置或公钥，这提供了自然加密基元具有源自标准硬度假设的适应性硬度的首个构建。
We construct the first general secure computation protocols that require no trusted in- frastructure other than authenticated communication, and that satisfy a meaningful notion of security that is preserved under universal composition—assuming only the existence of enhanced trapdoor permutations. The notion of security fits within a generalization of the “angel-based” framework of Prabhakaran and Sahai (STOC’04) and implies super-polynomial time simulation security. Security notions of this kind are currently known to be realizable only under strong and specific hardness assumptions.
A key element in our construction is a commitment scheme that satisfies a new and strong notion of security. The notion, security against chosen-commitment-attacks (CCA security), means that security holds even if the attacker has access to an extraction oracle that gives the adversary decommitment information to commitments of the adversary’s choice. This notion is stronger than concurrent non-malleability and is of independent interest. We construct CCA- secure commitments based on standard one-way functions, and with no trusted set-up. To the best of our knowledge, this provides the first construction of a natural cryptographic primitive having adaptive hardness from standard hardness assumptions, using no trusted set-up or public keys.