An asymmetric algorithm USES a different key for encrypting or decrypting the message; one of the keys must be kept secret, and the other key is usually made public.
非对称算法使用不同的密钥对消息进行加密或解密；其中一个秘钥必须是秘密的，而另一个密钥通常是公开的。
2
GnuPG allows encrypting and signing your data and communication, and features a versatile key-management system and access modules for all kinds of public key directories.
GnuPG支持数据和通信的加密和签名，且以一个多功能的密钥管理系统和各种公钥目录的访问模块为特色。
3
To encrypt file data, an encryption key password must be selected, which Tivoli Storage Manager uses to generate the encryption key for encrypting and decrypting the file data.