A cryptographic key that is used for both encryption and decryption, enabling the operation of a
symmetric key cryptography scheme.
Extended Definition: Also, a cryptographic algorithm that uses a single key (i.e., a secret key) for both encryption of plaintext and decryption of ciphertext.
Adapted from: CNSSI 4009.
Source: NICCS™ Portal Cybersecurity Lexicon, National Initiative for Cybersecurity Careers and Studies (https://niccs.us-cert.gov/glossary) as of 11 November 2015, Global Standards