Cryptography - Simplified - Asymmetric Encryption
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The document provides an overview of asymmetric encryption, highlighting key algorithms such as RSA, Diffie-Hellman, and elliptic curve cryptography. It explains how RSA employs a pair of keys (private and public) for secure communication, ensuring integrity, confidentiality, and non-repudiation. The document also outlines the basic premise of RSA encryption and decryption processes, along with a reference link for further understanding of RSA key generation.
Cryptography - Simplified - Asymmetric Encryption
- 1. Cryptography - Asymmetric Encryption 5 minutes series Abdul Manaf Vellakodath Security Architect
- 2. Asymmetric Encryption - Overview ● There are many different Asymmetric implementations around. Some of them are: ○ Diffie-Hellman (Key Exchange) ○ RSA ○ Elliptic Curve ● RSA is the most popular commercially used Asymmetric Algorithm from three cryptographers: ○ Rivest ○ Shamir ● Diffie Hellman is a Key Exchange mechanism ● RSA is also called Public Key encryption due to its nature of keys
- 3. Encryption and Decryption using Asymmetric Algorithm Asymmetric Key Encryption Algorithm Plain Text! s8sdfdvsja9 qj7*jsdsf$ks df.8sd*asfyl dywkkeykk Ciphertext Decryption Algorithm Plain Text! Asymmetric Key < One key to encrypt and the other Key to Decrypt>
- 4. RSA - Basic Premises ● The data encrypted with a Private Key can only be decrypted with its corresponding Public Key. ● The data encrypted with a Public Key can only be decrypted with its corresponding Private Key. ● The Sender has a Key called Private Key. This key is secret. It is never transferred out of his computer. Note: If someone finds this key, he could impersonate the sender. ● Everyone else, who wants to communicate with the Sender is given a key called the Public Key. Note: This key is generated as part of the earlier Private Key generation process. ● The Private and Public Keys comes in a pair when we talk about RSA Public Key encryption.
- 5. RSA Public Key Encryption - Features ● Integrity ○ Say: ■ M is the Message ■ MDh1 is the Message Digest (hash) ■ MDe is the encrypted (with the Sender’s Private Key) form of MD ○ Send M and MDe to the Receiver. ○ Receiver will: ■ Decrypts the MDe to find the MDh1. ■ Generate MDh2 again from M. ● Confidentiality: Use the Public Key to encrypt the message and send it to the user. Receiver uses his Private Key (secret) to decrypt the information, thus passing information secretly, achieving confidentiality. ● Non-repudiation: IF the Sender uses his Private Key to encrypt a message, anyone who has the respective Public Key could decrypt his message. Since the Sender is the only one possessing the Private Key, only the Sender could have sent the message. This is called non-repudiation.
- 6. RSA Encryption Algorithm ● Let us say: ○ Message = 65 (we want to encrypt this) ○ Public Key (n = 3233, e = 17) ○ Private Key (d = 2753) ● Encryption function: i.e. ● Decryption function: i.e. Note: The encryption using the Private Key s reversible using the Public Key. The reverse is ● Refer the following link to understand how the RSA Keys are generated: http://www.slideshare.net/AbdulManafV ellakodat/cryptography-simplified-key- generation-asymmetric-keys