信息技术.安全技术.加密算法.第2部分:不对称密码

[中文适用范围]： ISO/IEC 18033 的这一部分指定了几种非对称密码。 这些规范一般规定了此类密码的功能接口和正确使用方法，以及几种特定非对称密码的精确功能和密文格式（尽管符合要求的系统可以选择使用替代格式来存储和传输密文） 。 规范性附录（附录 A）给出了与 ISO/IEC 18033 本部分中指定的算法相关联的对象标识符、公钥和参数结构的 ASN.1 语法。 但是，这些规范并未规定用于可靠地获取密钥的协议。 公钥，用于证明拥有私钥，或用于验证公钥或私钥；有关此类关键管理问题的指导，请参阅 ISO/IEC 11770-3。 ISO/IEC 18033 本部分规定的非对称密码在第 7.6 条中说明。 注：简而言之，非对称密码是： ——ECIES-HC； PSEC-HC； ACE-HC：基于ElGamal加密的通用混合密码； ——RSA-HC：基于 RSA 变换的通用混合密码； ——RSAES：应用于 RSA 变换的 OAEP 填充方案； ——HIME(R)：基于因式分解难度的方案。 [外文原描述]： ISO/IEC 18033-2:2006 specifies encryption systems (ciphers) for the purpose of data confidentiality. The primary purpose of encryption (or encipherment) techniques is to protect the confidentiality of stored or transmitted data. An encryption algorithm is applied to data (often called plaintext or cleartext) to yield encrypted data (or ciphertext); this process is known as encryption. The encryption algorithm should be designed so that the ciphertext yields no information about the plaintext except, perhaps, its length. Associated with every encryption algorithm is a corresponding decryption algorithm, which transforms ciphertext back into its original plaintext. An asymmetric, i.e. public-key, encryption scheme allows a sender to use a recipient's public key to transmit an encryption of a message to the receiver, who can use his secret key to decrypt the given ciphertext, thereby obtaining the original message. Such a scheme should be secure in the sense that no information about the message should be leaked to a (resource-bounded) attacker, even if that attacker mounts a so-called 'chosen ciphertext' attack, in which he may obtain decryptions of other ciphertexts. This is the strongest type of attack that has been proposed for a public-key encryption scheme. ISO/IEC 18033-2:2006 specifies the functional interface of such a scheme, and in addition specifies a number of particular schemes that appear to be secure against chosen ciphertext attack. The different schemes offer different trade-offs between security properties and efficiency.