Information Security
Mamoona Jabbar
,Information Security
Topic: Cryptology Techniques
, Cryptographic Systems - History
Before proceeding further, you need to know some facts about historical
cryptosystems
• All of these systems are based on symmetric key encryption scheme.
• The only security service these systems provide is confidentiality of
information.
• Unlike modern systems which are digital and treat data as binary numbers,
the earlier systems worked on alphabets as basic element.
These earlier cryptographic systems are also referred to as Ciphers. In general, a
cipher is simply just a set of steps (an algorithm) for performing both an
encryption, and the corresponding decryption.
Mamoona Jabbar
,Information Security
Topic: Cryptology Techniques
, Cryptographic Systems - History
Before proceeding further, you need to know some facts about historical
cryptosystems
• All of these systems are based on symmetric key encryption scheme.
• The only security service these systems provide is confidentiality of
information.
• Unlike modern systems which are digital and treat data as binary numbers,
the earlier systems worked on alphabets as basic element.
These earlier cryptographic systems are also referred to as Ciphers. In general, a
cipher is simply just a set of steps (an algorithm) for performing both an
encryption, and the corresponding decryption.
