Cryptography is a method of storing and transmitting data in a particular form so that only those for whom it is intended can read and process it. Cryptography includes techniques such as microdots, merging words with images, and other ways to hide information in storage or transit.
• Cryptography is a method of storing and transmitting data in a particular form
so that only those for whom it is intended can read and process it.
• Cryptography includes techniques such as microdots, merging words with
images, and other ways to hide information in storage or transit.
in today’s computer-centric world, cryptography is most often
associated with scrambling plaintext (ordinary text, sometimes referred to as
clear text) intocipher text (a process called encryption), then back again (known
as decryption). Individuals who practice this field are known as cryptographers.
• The science or study of the techniques of secret writing, especially codeand
cipher systems, methods, and the like.
• Compare cryptanalysis.
• There are five primary functions of cryptography today:
• Privacy/confidentiality: Ensuring that no one can read the message except
the intended receiver.
• Authentication: The process of proving one’s identity.
• Integrity: Assuring the receiver that the received message has not been
altered in any way from the original.
• Non-repudiation: A mechanism to prove that the sender really sent this
• Key exchange: The method by which crypto keys are shared between sender
• How this works?
• In cryptography, we start with the unencrypted data, referred to as
plaintext. Plaintext is encrypted into cipher text, which will in turn (usually)
be decrypted into usable plaintext.
• The encryption and decryption is based upon the type of cryptography
scheme being employed and some form of key. For those that like formulas,
this process is sometimes written as:
• C = Ek(P)
• P = Dk(C)
• where P = plaintext, C = cipher text, E = the encryption method, D = the
decryption method, and k = the key.
• In many of the descriptions below, two communicating parties will be