DIGITAL SIGNATURE IMPLEMENTATION

1
DIGITAL SIGNATURE
IMPLEMENTATION

• FINAL PROJECT PROPOSAL
• SHANTHAN MUDHASANI
• SHAIK SHANAWAZ

2
DIGITAL SIGNATURES

• A digital signature or digital signature scheme
  is a type of asymmetric cryptography.
• First described by Whitfield Diffie and Martin
  Hellman
• Provide a high level of assurance that the
  digital signature is genuinely the signer's

3
HOW IT WORKS

• Using special software, you obtain a message
  hash of the message.
• You then use a private key that you have to
  encrypt the hash.
• The encrypted hash becomes your digital
  signature of the message.
• At the other end
• To make sure it's intact and from you, your
  receiver makes a hash of the received message.
• Receiver then uses your public key to decrypt the
  message hash or summary.
• If the hashes match, the received message is
  valid.

4
MD5-Message Digest Algorithm

• We begin by supposing that we have a b-bit
  message as input,and that we wish to find its
  message digest
• Step 1. Append Padding Bits
• Step 2. Initialize MD Buffer
• Step 3. Process Message in 16-Word Blocks
• Step 4. Output

5
RSA ALGORITHM

• Sender A does the following-
• Obtains the recipient B's public key (n, e).
• Represents the plaintext message as a positive
  integer m
• Computes the cipher text c me mod n.
• Sends the cipher text c to B.
• Recipient B does the following-
• Uses his private key (n, d) to compute m cd
  mod n.
• Extracts the plaintext from the message
  representative m.

6
KEY GENERATION

• Select random prime numbers p and q, and check
  that p ! q
• Compute modulus n pq
• Compute phi (p - 1)(q - 1)
• Select public exponent e, 1 lt e lt phi such that
  gcd(e,phi) 1
• Compute private exponent d e - 1 mod phi
• Public key is n, e, private key is (n,d)
• Encryption c me mod n, decryption m cd
  mod n

7
SYSTEM REQUIREMENTS

• LEDS
• MESSAGE SENT
• MESSAGE RECEIVED
• BUTTONS
• PRINT OUTPUT
• CURSOR CONTROL
• MESSAGE DISPLAY
• SWITCHES
• RESET
• ERROR INSERT ENABLE
• KEYBOARD
• USER INPUT
• MONITOR
• TO DSPLAT THE OUTPUT

8
BLOCK DIAGRAM

9
BLOCK DIAGRAM
10
PRE-SYNTHESIS SIMULTION
11
LAYOUT