Symmetric Encryption and
Symmetric Encryption and
Message Confidentiality
Message Confidentiality
also known as: conventional encryption, secret-
also known as: conventional encryption, secret-
key, or single-key encryption
key, or single-key encryption
only alternative before public-key crypto in 70’s
only alternative before public-key crypto in 70’s
still most widely used
still most widely used
alternative
alternative
has ingredients: plaintext, encryption algorithm, secret
has ingredients: plaintext, encryption algorithm, secret
key, ciphertext, and decryption algorithm
key, ciphertext, and decryption algorithm
generically classified along dimensions of:
generically classified along dimensions of:
1.
1.
type of operations used
type of operations used
2.
2.
number of keys used
number of keys used
3.
3.
way in which the plaintext is processed
way in which the plaintext is processed
