Secret key cryptography uses a conventional algorithm such as the
Data Encryption Standard (DES) algorithm
or the Advanced Encryption
Standard (AES) algorithm that are supported by
ICSF. Another
term for secret key cryptography is symmetric cryptography. To have
intelligent cryptographic communications between two parties who are
using a conventional algorithm, this criteria must be satisfied:
- Both parties must use the same cryptographic algorithm.
- The cryptographic key that the sending party uses to encipher
the data must be available to the receiving party to decipher the
data.
Figure 1 is a simplified illustration of
the cryptographic components that are needed to encipher and decipher
data in a secret key cryptographic system. In this system, Tom and
Linda have established a secure communications channel by sharing
a secret key. Tom enciphers the plaintext by using the algorithm and
the secret key before sending it to Linda. When she receives the ciphertext,
Linda deciphers it using the same algorithm and the same secret key.
In a secret key system, it is critically important to maintain the
secrecy of the shared key.
Figure 1. Enciphering and deciphering data
in a secret key system