- 1. RESEARCH APPROACH IN CRYPTOGRAPHY Presented By: Mostak Ahmed Guided By: Rupam Kr Sharma
- 2. INTRODUCTION •A cryptographic algorithm, or cipher, is a mathematical function used in the encryption and decryption process. •A cryptographic algorithm works in combination with a key a word, number, or phrase to encrypt the plaintext. •The security of encrypted data is entirely dependent on two things: the strength of the cryptographic algorithm and the secrecy of the key. CRYPTOGRAPHY
- 3. OBJECTIVE •The objective of the project is to do a analytical study of the existing cryptographic systems ,their response to the varying number of inputs and comparative study of them(time complexity, space complexity). •Also to study and simulate the vulnerabilities of the algorithm to different cryptanalytic attacks if possible on them. The project is also taking care of their comparative study. CRYPTOGRAPHY
- 4. Common Attacks Against Security Over Network •Tapping the wire: To get access to clear text data and passwords •Impersonation: To get unauthorized access to data or to create unauthorized e-mails, orders, etc. •Denial-of-service: To render network resources non-functional. •Replay of messages: To get access to information and change it in transit. •Guessing of Keys Passwords: To get access to encrypted data and passwords •Virus: To destroy data. CRYPTOGRAPHY
- 5. Solutions For Attacks Against Security Over Networks •Encryption: To protect data and passwords. •Authentication: By using digital signatures and certificates this will do verify who is sending data over the network. •Authorization: To prevent improper access of data over the network. •Integrity checking: To protect against improper alteration of messages. •Non-repudiation: To make sure that an action cannot be denied by the person who performed it. CRYPTOGRAPHY
- 7. SPECIFICATION •Hardware Requirements: Ram: 1GB, Hard disk: 10GB Processor: Pentium IV 3GHz •Software Requirements: Mat lab Operating System: windows CRYPTOGRAPHY
- 8. RSA ALGORITHM Key generation: •Step 1: Select random prime numbers p and q, and check that p != q •Step 2: Compute modulus n = pq •Step 3: Compute phi, •Step 4: ɸ= (p - 1)(q - 1) •Step 5 : Select public exponent e, 1 < e <ɸ •Step 6: such that gcd(e,ɸ) = 1 •Step 7: Compute private exponent d = e-1 mod ɸ •Step 8: Public key is {n, e}, private key is d •Step 9: Encryption: c = me mod n •Step 10: Decryption: m = c dmod n CRYPTOGRAPHY
- 10. CAESAR ALGORITHM •Step 1: Open input file •Step 2: find Unicode of the input file and put in y. •Step 3: calculate y= y + 3 •Step 4: Encrypted form (z)of the file contents i.e., CHYPER TEXT •Step 5: character of y. •Step 6: w= Unicode of z •Step 7: w= w-3 •Step 8: character of w •Step 9: Decrypt the chyper text to get plain text CRYPTOGRAPHY
- 12. OBSERVATION •We are analysis some of the algorithm like DES, AES, RSA, Ceaser, Playfair etc. And we Implemented RSA and Ceaser using MATLAB we are testing with various types of input and observed the respective output and their time complexity. When we took a simple file input for RSA we found the time of execution as 0.312 and in case of Ceaser we getting the time complexity as 0.012s. Now we are trying to implement Playfair, DES which is going in process but not yet complete. Once we complete the Analysis of the previous Algorithm if time permits we are trying to implement our own Algorithm where we are trying to take care of the time and space complexity. CRYPTOGRAPHY
- 15. CRYPTOGRAPHY