ISO 20215:2015中包含的算法建议用于要求信息（如数据、语音和视频）保密、认证或认证保密的空间任务。这些算法可用于任何或所有任务通信链路，如前向空间链路（如遥控）、返回空间链路（如遥测、科学数据）以及整个地面数据网络。它们还可以用来确保存储数据的机密性和真实性。 对称算法假设所有通信实体都拥有一个共享密钥（即？密钥），该密钥使它们能够加密、解密和验证它们之间共享的信息。共享秘密的分发和管理方式（密钥管理）不在本文件范围内。 有关密钥管理的更多信息，请参见空间任务密钥管理概念（参考[B22]）。

The algorithms contained in ISO 20215:2015 are recommended for use on space missions with a requirement for information (e.g., data, voice, and video) confidentiality, authentication, or authenticated confidentiality. The algorithms may be employed on any or all mission communications links such as the forward space link (e.g., telecommand), the return space link (e.g., telemetry, science data), as well as across the ground data network. They could as well be used to ensure confidentiality and authenticity of stored data. A symmetric algorithm assumes that all communicating entities possess a shared secret (i.e., a?key') which enables them to encrypt, decrypt, and authenticate information shared among them. The manner in which the shared secret is distributed and managed (key management) is not within the scope of this document. Further information on key management can be found in Space Missions Key Management Concept (reference [B22]).