• Share
  • Email
  • Embed
  • Like
  • Save
  • Private Content
Cryptography its history application and beyond
 

Cryptography its history application and beyond

on

  • 1,094 views

History of Cryptography and Its Application

History of Cryptography and Its Application

Statistics

Views

Total Views
1,094
Views on SlideShare
1,094
Embed Views
0

Actions

Likes
0
Downloads
22
Comments
0

0 Embeds 0

No embeds

Accessibility

Categories

Upload Details

Uploaded via as Microsoft PowerPoint

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Processing…
Post Comment
Edit your comment
  • The key can only be used once and must be kept entirely secret from all except the sender and receiver, creating a distribution problem. If these problems are not overcome, particularly the randomness of the key, the one-time pad is no longer unbreakable. Even if it is theoretically secure, it may be insecure in practice.
  • NBS : National Bureau of Standards NIST : National Institute of Standards and Technology IBM : International Business Machines Corporation In modern cryptography, symmetric key ciphers are generally divided into stream ciphers and block ciphers. Block ciphers operate on a fixed length string of bits A parity bit is a bit that is added to ensure that the number of bits with the value one in a set of bits is even or odd. Parity bits are used as the simplest form of error detecting code
  • Diffie and Martin Hellman's paper New Directions in Cryptography was published in 1976. It introduced a radically new method of distributing cryptographic keys, that went far toward solving one of the fundamental problems of cryptography, key distribution. It has become known as Diffie–Hellman key exchange The RSA algorithm was publicly described in 1977 but given the relatively expensive computers needed to implement it at the time, it was mostly considered a curiosity and, as far as is publicly known, was never deployed. His discovery, however, was not revealed until 1998 due to its top-secret classification, and Rivest, Shamir, and Adleman devised RSA independently of Cocks' work. The prime factors must be kept secret. Anyone can use the public key to encrypt a message, but with currently published methods, if the public key is large enough, only someone with knowledge of the prime factors can feasibly decode the message
  • Diffie and Martin Hellman's paper New Directions in Cryptography was published in 1976. It introduced a radically new method of distributing cryptographic keys, that went far toward solving one of the fundamental problems of cryptography, key distribution. It has become known as Diffie–Hellman key exchange The RSA algorithm was publicly described in 1977 but given the relatively expensive computers needed to implement it at the time, it was mostly considered a curiosity and, as far as is publicly known, was never deployed. His discovery, however, was not revealed until 1998 due to its top-secret classification, and Rivest, Shamir, and Adleman devised RSA independently of Cocks' work. The prime factors must be kept secret. Anyone can use the public key to encrypt a message, but with currently published methods, if the public key is large enough, only someone with knowledge of the prime factors can feasibly decode the message
  • Identification is the process of verifying someone's or something's identity Authentication is similar to identification, in that both allow an entity access to resources (such as an Internet account), but authentication is broader because it does not necessarily involve identifying a person or entity. Authentication merely determines whether that person or entity is authorized for whatever is in question
  • Cryptology: the study of cryptanalysis and cryptography Cryptanalysis : The "breaking" of codes and ciphers Steganography is about hiding messages i.e. hides even the existence of a message In Greek: Steganos = covered and Graphein = to write Historically, secret messages were often hidden (or memorized) Today, steganography is used primarily to protect digital rights “ watermarking” copyright notices “ fingerprinting” a serial ID   Cryptography does not hide the existence of messages i.e. hiding the meaning of messages In Cryptography, the meaning of the message is hidden, not its existence In Greek:Kryptos = “hidden” and gráphō (writing) Historically, and also today, encryption involves: Substitution: replacing each character with a different character Hebrew ATBASH Kama-Sutra suggests that women learn to encrypt their love messages by substituting pre-paired letters (4 th Century AD) Cipher – replace letters Code – replace words   transposition : Moves the letter around Sparta’s scytale is first cryptographic device (5 th Century BC):Message written on a leather strip, which is then unwound to scramble the message

Cryptography its history application and beyond Cryptography its history application and beyond Presentation Transcript