Cryptography with a shared secret known to all parties. The major algorithms are DES, IDEA, TwoFish, BlowFish, as well as a few others.
These algorithms generally also used in most PublicKeyEncryption systems as workhorses once a trusted channel has been established by other means, since they're much less comutationally intensive and better suited for bulk data transfers.
Compare: PublicKeyEncryption
2 pages link to ConventionalCryptography:
