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.

1. A SURVEY OF CRYPTOGRAPHIC
ALGORITHMS
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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.
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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.
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4. CRYPTOGRAPHY
CONCEPT
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5. APPROACHES
• It is an systematic approach and it has 3segments contains
> Security attack
> Security mechanism
> Security service
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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
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7. ACTIVE ATTACK
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8. PASSIVE ATTACK
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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.
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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
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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
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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
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13. SYMMETRIC CIPHER
MODEL
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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

15. Public key cryptography
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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)
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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
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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
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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.
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20. THANK U
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