Comprehensive Tutorial on Simplified Data Encryption Standard (S-DES) by Amit Kumar

Download 1M+ code from https://codegive.com/b45540e simplified data encryption standard (s-des) algorithm: a comprehensive tutorial with python code this tutorial delves into the simplified data encryption standard (s-des), a simplified version of the data encryption standard (des) algorithm. while des is a complex block cipher used for robust encryption, s-des is designed for educational purposes, allowing us to understand the fundamental principles of block ciphers without getting bogged down in the intricacies of des. **understanding s-des:** s-des is a symmetric-key block cipher. this means that the same key is used for both encryption and decryption. it operates on 8-bit blocks of plaintext and uses a 10-bit key. the encryption and decryption processes involve a series of rounds, each consisting of permutation, substitution, and xor operations. **key concepts:** * **symmetric-key cipher:** uses the same key for encryption and decryption. * **block cipher:** operates on fixed-size blocks of data (in s-des, 8 bits). * **key generation:** a 10-bit key is transformed into two 8-bit subkeys (k1 and k2) used in different rounds. * **permutation:** rearranging the order of bits. * **substitution:** replacing bits based on a predefined lookup table (s-boxes). * **xor (exclusive or):** a logical operation that outputs 1 if the inputs are different, and 0 if they are the same. **s-des algorithm overview:** the s-des algorithm consists of the following steps: 1. **key generation:** generate two subkeys (k1 and k2) from the initial 10-bit key. 2. **initial permutation (ip):** rearrange the bits of the 8-bit plaintext using a predefined permutation table. 3. **round 1:** * **feistel function (fk):** applies a combination of expansion/permutation, xor with k1, s-box substitution, and permutation. * **swap:** swaps the left and right halves of the data. 4. **round 2:** * **feistel function (fk):** applies the same feistel function as in round 1, but xoring with k2 instead of k1. * **swap (not in this ... #SDE #DataEncryption #AmitKumar Simplified Data Encryption Standard S-DES Amit Kumar data encryption cryptography symmetric key encryption block cipher encryption algorithm security data privacy key generation plaintext ciphertext digital security information protection