Caeser cipher for lab exp 1 batch 1 teams

CNS LAB QUESTIONS FOR BATCH 1 TEAMS TEAM 1: Alice wants to send a secret message to Bob using a Caesar cipher with a shift of 3. If her message is "HELLO", what will the encrypted message be? TEAM 2: Bob receives a message encrypted with a Caesar cipher and sees the text "KHOOR". He knows the shift used for encryption is 3. What is the original message? TEAM 3: Carla encrypts the message "WORLD" using a Caesar cipher with a shift of 5. What will the encrypted message look like? TEAM 4: Dave receives an encrypted message "ZRUOG" and is told that the message was encrypted with a shift of 3. What was the original message before encryption? TEAM 5: Frank encrypts the message "HELLO WORLD!" with a Caesar cipher using a shift of 4. what will the final encrypted text be? TEAM 6: Grace receives an encrypted message "QEB NRFZH YOLTK CLU GRJMP LSBO QEB IXWV ALD". She knows it was encrypted using a Caesar cipher with a shift of 23. What is the original message?

ASSIGNMENT 1

Assignment Questions on Substitution Techniques Caesar Cipher Analysis: Encrypt the following plaintext using the Caesar Cipher with a shift of 3: "CRYPTOGRAPHY IS FUN". Decrypt the following ciphertext, which was encrypted using the Caesar Cipher with a shift of 5: "GZWKXNAFWJY NX KZSJ". Monoalphabetic Cipher: Encrypt the following message using a given substitution table where ‘A’ is substituted with ‘M’, ‘B’ with ‘N’, ..., ‘Z’ with ‘L’: "SECURITY IS IMPORTANT". Playfair Cipher: Construct a 5x5 Playfair cipher matrix using the keyword "KEYWORD". Encrypt the message "HELLO WORLD" using this matrix. Hill Cipher: Using the Hill Cipher with a 2x2 key matrix [[3, 3], [2, 5]], encrypt the plaintext "HELP". . Vigenère Cipher: Encrypt the plaintext "ATTACKATDAWN" using the Vigenère Cipher with the keyword "LEMON". Describe how frequency analysis can be used to break the Vigenère Cipher and suggest a way to mitigate this attack. Assignment Questions on Transposition Techniques Rail Fence Cipher: Encrypt the message "NETWORK SECURITY" using the Rail Fence Cipher with 3 rails. Decrypt the following Rail Fence Cipher text with 2 rails: "ETWEKR NETCUIY". Real-World Applications: Identify a real-world application of substitution techniques and transposition techniques in modern cryptographic systems. Discuss the significance of each technique and why it is still relevant today.

ASYMMETRIC KEY CRYPTOGRAPHY

1.Factor the number 4557 into prime factors using Fermat's factorization method. 2. If p=11, a prime number, what is the value of φ(11)? 3.Alice and Bob want to establish a shared secret key using the Diffie-Hellman key exchange protocol. They agree on a public base 𝑔 = 5 g=5 and a prime modulus 𝑝 = 23 p=23. Alice chooses her private key 𝑎 = 6 a=6. Bob chooses his private key 𝑏 = 15 b=15. What value does Alice send to Bob? What value does Bob send to Alice? What is the shared secret key they both compute? 4. Bob wants to send Alice a secure message using the RSA encryption system. Alice has chosen the following RSA parameters: 𝑝 = 11 p=11 𝑞 = 13 q=13 Calculate the modulus 𝑛 n and Euler’s totient 𝜑 ( 𝑛 ) φ(n). Alice chooses a public exponent 𝑒 = 7 e=7. Verify that 𝑒 e is a valid choice. Calculate Alice’s private key 𝑑 d. Bob wants to send the message 𝑚 = 5 m=5 to Alice. Encrypt the message using Alice’s public key. How will Alice decrypt the message to retrieve the original message 𝑚 m?