RSA Algoritmn
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This document provides an overview of symmetric encryption, asymmetric encryption, and the RSA algorithm. It discusses how symmetric encryption uses a shared key for encryption and decryption, while asymmetric encryption uses public and private key pairs. It then explains that RSA is an asymmetric encryption algorithm that is widely used today. Specifically, RSA is based on the difficulty of factoring large prime numbers, where a public key is used to encrypt messages and a private key is used to decrypt them.
RSA Algoritmn
- 1. RSAAlgorithm By: Dr. Kapil Gupta 1
- 2. CONTENTS • Symmetric Encryption • Symmetric Cipher Model • Asymmetric Encryption • Asymmetric Cipher Model • RSAAlgorithm 2
- 3. Symmetric Encryption • Conventional / Private-key / Single-key • sender and recipient share a common key • all classical encryption algorithms are private- key • was only type prior to invention of public-key in 1970’s • most widely used 3
- 4. • Conventional Encryption: encryption and decryption are performed using the same key. • Symmetric encryption transforms plaintext into ciphertext using a secret key and an encryption algorithm. • Using the same key and a decryption algorithm, the plaintext is recovered from the ciphertext. 4
- 6. Asymmetric Encryption • 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 • why asymmetric ? – those who encrypt messages or verify signatures cannot decrypt messages or create signatures 6
- 8. • RSA (Rivest–Shamir–Adleman) is one of the first public-key cryptosystems and is widely used for secure data transmission. • In such a cryptosystem, the encryption key is public and distinct from the decryption key which is kept secret (private). • In RSA, this asymmetry is based on the practical difficulty of factoring the product of two large prime numbers, the "factoring problem". • The RSA algorithm is the most popular and proven asymmetric key cryptographic algorithm. • The RSA algorithm is based on the mathematical fact that it is easy to find and multiply large prime numbers together, but it is extremely difficult to factor their product. RSAAlgorithm 8
- 9. • The real challenge in the case of RSA is the selection and generation of the public and private keys. • Let us now understand how the public and private keys are generated, using them, how we can perform encryption and decryption in RSA. 9
- 10. EXAMPLE: 10
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- 13. REFERENCES 1. Cryptography and Network Security by Atul Kahate. 2. Cryptography and Network Security by William Stallings. 13
- 14. Thank You 14