$ hybrid encryption
(I) An application of cryptography that combines two or more
encryption algorithms, particularly a combination of symmetric and
asymmetric encryption. Examples: digital envelope, MSP, PEM, PGP.
(Compare: superencryption.)
Tutorial: Asymmetric algorithms require more computation than
equivalently strong symmetric ones. Thus, asymmetric encryption is
not normally used for data confidentiality except to distribute a
symmetric key in a hybrid encryption scheme, where the symmetric
key is usually very short (in terms of bits) compared to the data
file it protects. (See: bulk key.)