Encryption Techniques
– A good encryption technique has the following properties:
• It is relatively simple for authorized users to encrypt and decrypt
data.
• It depends not on the secrecy of the algorithm, but rather on a
parameter of the algorithm called the encryption key, which is
used to encrypt data.
– In a symmetric-key encryption technique, the encryption key is also used
to decrypt data.
– public-key (also known as asymmetric-key) encryption techniques, there
are two different keys, the public key and the private key, used to encrypt
and decrypt the data.
• Its decryption key is extremely difficult for an intruder to
determine, even if the intruder has access to encrypted data. In
the case of asymmetric-key encryption, it is extremely difficult to
infer the private key even if the public key is available.