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This document surveys cryptographic algorithms including DES (block cipher), RC4 (stream cipher), SHA-1 (hash), and RSA (public-key cryptography). It discusses how cryptography encrypts messages from sender to receiver using cipher text to hide messages from hackers. Symmetric algorithms like DES use the same key for encryption and decryption while asymmetric algorithms like RSA use public and private key pairs. The document also examines the RSA encryption algorithm and how it generates keys based on prime numbers.
cryptography deepan fav subject
- 1. A SURVEY OF CRYPTOGRAPHIC ALGORITHMS 1
- 2. ABSTRACT • When survey a variety of cryptographic algorithms falling into four main categories: DES (block cipher), RC4 (stream cipher), SHA-1(hash) and RSA (public-key cryptography). • We are using cryptography method in this survey which is related to the security concepts. 2
- 3. CRYPTOGRAPHY • Cryptographic algorithms are a means of discreetly conveying secret information between one party and another. • The plaintext message is encrypted from sender side using a crypto-graphic algorithm and decrypted the plaintext to the receiver side. • This will encrypt and decrypt by using cipher text which is convert to duplicate message to hide the message from the hacker. 3
- 5. APPROACHES • It is an systematic approach and it has 3segments contains > Security attack > Security mechanism > Security service 5
- 6. SECURITY ATTACK • Any action that compromises the security of information owned by an organization. • The attack teamed as two types which is ->Active attack ->Passive attack 6
- 9. SECURITY MECHANISM • The mechanisms are divided into those that are implemented in a mechanism. • It has specific protocol layer, such as TCP or an application-layer protocol. • That are not specific to any particular protocol layer or security service either detect or prevent. 9
- 10. SECURITY SERVICES • It is processing service or communication services mainly used for protected the resources • It is implemented by security mechanism * Authentication * Access control * Data confidentiality 10
- 11. CLASSICAL ENCRYPTION TECHNIQUES • Symmetric encryption, also referred to as conventional encryption or single- key encryption • It was only type of encryption in use prior to the development of public key encryption in the 1970s. • It remains by far the most widely used of the two types of encryption. -Symmetric -Assymmetric 11
- 12. SYMMETRIC ALGORITHMS • Symmetric algorithms are key-based algorithms that use the same key for encryption and decryption. • The Caesar cipher mentioned & Both block ciphers and stream ciphers fall into this category • Stream ciphers are symmetric algorithms that operate on plaintext input one bit (or byte) at a time. • Block ciphers are symmetric algorithms that operate on larger blocks, usually 64 bits in size 12
- 14. Public key cryptography • public-key/two-key/asymmetric cryptography involves the use of two keys: • a public-key, which may be known by anybody, and can be used to encrypt messages, and verify signatures • a private-key, known only to the recipient, used to decrypt messages, and sign (create) signatures is Asymmetric • Because those who encrypt messages or verify signatures cannot decrypt messages or create signatures 14
- 16. Data encryption standards (DES) • Most widely used block cipher in world • Adopted in 1977 by NBS (now NIST) • Encrypts 64-bit data using 56-bit key has widespread • It has been considerable controversy over its security • Y = IP-1(X) = IP-1(IP(M)) (-1 INVERSE) 16
- 17. RSA • The RSA encryption/decryption algorithms are a type of public key cryptography named for Ron Rivest, Adi Shamir and Leonard Adleman, who rst presented the algorithm in 1977 • c = me mod n. • m = cd mod n 17
- 18. RSA Key generation Algorithm 3 RSA Key Generation •1: procedure Get Keys(b) ->Generates keys based on b-bit primes •2: p; q primes of bit-length b •3: n p q -> First public key •4: (p- 1)(q- 1) •5: e e such that gcd(e; ) = 1 -> Second public key •6: d (e-1) mod -> Private key •7: return n; e; d •8: end procedure 18
- 19. CONCULSION • The purpose of this research was to learn about cryptographic algorithms and to analyze • The efficiency of the RSA encryption algorithm when implemented with direct subroutines and in direct languages. • Future work could include implementing the algorithm in languages that better allow bit-level manipulation, such as C. 19
- 20. THANK U 20