Public Key

The public part of an asymmetric key pair that is typically used to verify signatures or encrypt data.
SOURCE: FIPS 201; SP 800-63

A cryptographic key, used with a public key cryptographic algorithm, that is uniquely associated with an entity and may be made public. In an asymmetric (public) cryptosystem, the public key is associated with a 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 is signed by the corresponding private key,
2) Encrypt keys that can be decrypted by the corresponding private key, or
3) Compute a shared secret during a key-agreement transaction.
SOURCE: SP 800-57 Part 1

A cryptographic key used with a public key cryptographic algorithm, uniquely associated with an entity, and which may be made public; it is used to verify a digital signature; this key is mathematically linked with a corresponding private key.
SOURCE: FIPS 196

A cryptographic key used with a public key cryptographic algorithm that is uniquely associated with an entity and that may be made public.
SOURCE: FIPS 140-2

A cryptographic key that may be widely published and is used to enable the operation of an asymmetric cryptography scheme. This key is mathematically linked with a corresponding private key. Typically, a public key can be used to encrypt, but not decrypt, or to validate a signature, but not to sign.
SOURCE: CNSSI-4009