Symmetric key cryptography
algorithms are generally much less computationally intensive than asymmetric key cryptography algorithms.
Symmetric key cryptography is less computationally intensive and therefore much faster, especially for bulk
data encryption such as data transfers, and can run on appliances without dedicated cryptographic hardware.
The list that follows contains some of the common symmetric key cryptography algorithms that are in use
today:
Data Encryption Standard (DES): DES, one of the earliest and most common symmetric key
algorithms, was designed by IBM in the 1970s. DES was selected the official Federal Information
Processing Standard (FIPS) for the United States in 1976 and was adopted by the National Institute for
Standards and Technology (NIST) in 1977 for commercial and unclassified government applications.
DES is a block cipher that uses a 56-bit key to encrypt 64-bit datagram blocks.
DES is no longer considered very secure, mainly because the inherent 56-bit key size is too small. DES
has been known to be compromised in less than 24 hours.
Triple-DES (3DES): 3DES is a variant of DES. 3DES employs up to three 56-bit keys (168-bits) and
makes three encryption and decryption passes over the same datagram block.
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