1. Overview of Digital Signatures Introduction To Networks and Communications (CS 555) Presented by Bharath Kongara

2. What is a Digital Signature? An electronic signature that can be used to authenticate the identity of the sender of a message or the signer of a document.

3. Why Digital Signatures? To Provide Authenticity, Non-Repudiation and Integrity to electronic documents To use internet as the safe and secure medium for e-Commerce and e-Governance

4. Digital Signatures Each individual generates his own key pair ( Public key known to everyone and private key only to the owner) Private key - Used for making digital owner Public key – Used to verify the digital signature

5. How it works? Step 1: Getting a Private and Public Key Step 2: Signing an Electronic Document Initiate the signing process Create a digital signature Append the signature to the document

6. How it works? Step 3: Validating a Digital Signature (Receiver Side) Initiate the validation process Decrypt the digital signature Compares the document fingerprint with the calculated one

7. What is a Digital Certificate and who issues it? A digital certificate is an electronic document that uses a digital signature to bind together a public key with an identity. The CA issues an encrypted digital certificate containing the sender’s public key and a variety of other identification information.

8. Message Digest Data to be encoded -> Message Hash value(Message)->Message Digest or Digest Hash Functions MD4 MD5 SHA-1 SHA-2 are generally used

9. Uses of Digital Signature and Overall Function Authentication Integrity Non-repudiation

10. References http://en.wikipedia.org/wiki/Cryptographic_hash_function http://www.authorstream.com/Presentation/aSGuest41865- 360870-digital-signature-ccapresentation-1-science-technology-ppt- powerpoint/ http://www.arx.com/digital-signatures-faq/ http://en.wikipedia.org/wiki/Digital_signature http://www.webopedia.com/TERM/D/digital_certificate.html

11. Thank You