Key Management Glossary
| Term | Definition |
|---|---|
| Symmetric-key algorithm | A cryptographic algorithm that uses the same secret key for an operation and its complement (e.g., encryption and decryption). Also called a secret-key algorithm. |
| Symmetric key | A single cryptographic key that is used with a symmetric-key cryptographic algorithm, is uniquely associated with one or more entities, and is not made public (i.e., the key is kept secret). A symmetric key is often called a secret key. See Secret key. |
| Secret key | A single cryptographic key that is used with a symmetric-key cryptographic algorithm, is uniquely associated with one or more entities and is not made public (i.e., the key is kept secret). A secret key is also called a Symmetric key. The use of the term “secret” in this context does not imply a classification level but rather implies the need to protect the key from disclosure. |
| Public-key（asymmetric）cryptographic algorithm | A cryptographic algorithm that uses two related keys: a public key and a private key. The two keys have the property that determining the private key from the public key is computationally infeasible. |
| Asymmetric key algorithm | See Public-key cryptographic algorithm. |
| Key pair | A public key and its corresponding private key; a key pair is used with a public-key algorithm. |
| Public key | A cryptographic key used with a public-key cryptographic algorithm that is uniquely associated with an entity and that may be made public. In an asymmetric-key (public-key) cryptosystem, the public key has a corresponding private key. The public key may be known by anyone and, depending on the algorithm, may be used, for example, to: 1. Verify a digital signature that was generated using the corresponding private key, 2. Encrypt keys that can be decrypted using the corresponding private key, or 3. Compute a shared secret during a key-agreement transaction. |
| Private key | A cryptographic key used with a public-key cryptographic algorithm that is uniquely associated with an entity and is not made public. In an asymmetric-key (public-key) cryptosystem, the private key has a corresponding public key. Depending on the algorithm, the private key may be used, for example, to: 1. Compute the corresponding public key, 2. Compute a digital signature that may be verified by the corresponding public key, 3. Decrypt keys that were encrypted by the corresponding public key, or 4. Compute a shared secret during a key-agreement transaction. |
Reference
NIST
SP 800-57 Part 1 Rev.5 [PDF]