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Icai Digital Signature

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A simplified presentation on digital signature for ca ipcc students made by robin singh.

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Page 1: Icai Digital Signature
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I ROBIN SINGH WOULD LIKE TO TAKE THIS

OPPORTUNITY EXPRESS MY THANKS TO MY

RESPECTED TEACHERS

MRS.ROHINI SARASWAT AND MR. PANKAJ GARG

FOR THEIR VALUABLE GUIDANCE SUPPORT AND

ENCOURAGEMENT FOR THIS PROJECT WHO HAD

BEEN A GOOD INSPIRATION TO ME.

Acknowledgement

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1. DEFINITION

2. WHY DIGITAL SIGNATURE ?

3. DIFFERENCE BETWEEN PAPER SIGNATURE & DIGITAL SIGNATURE

4. HOW DOES DIGITAL SIGNATURE WORK ?

5. DIGITAL SIGNATURE CERTIFICATES(DSC)

6. CLASSES OF DIGITAL CERTIFICATES

7. BENEFITS AND CHALLENGES

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1. Digital signature simply means signature in digital form.

2. From the legal point of view , signature is a mark to authenticate a document with an intention to give it a legal effect.

3. As per section 3 of Information Technology Act, 2000, Digital signature means authentication of any electronic record by the subscriber by means of an electronic method.

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Electronic Record1. Very easy to make copies2. Very fast distribution3. Easy archiving and retrieval4. Copies are as good as original5. Easily modifiable6. Environmental Friendly

Because of 4 & 5 together, these lack authenticity

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Why Digital Signatures?•To provide Authenticity, Integrity and Non-repudiation to electronic documents•To use the Internet as the safe and secure medium for e-Commerce and e-Governance

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Paper signatures v/s Digital Signatures

Parameter Paper Electronic

Authenticity May be forged Can not be copied

Integrity Signature independent of the document

Signature depends on the contents of the document

Non-repudiation

a. Handwriting expert needed

b. Error prone

a. Any computer user

b. Error free

V/s

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HOW DOES DIGITAL SIGNATURE HOW DOES DIGITAL SIGNATURE WORK?WORK?

Digital signature works in two steps :

1.Creation of a digital signature

2.Verification of a Digital Signature

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Creation of a digital signatureCreation of a digital signature

A digital signature was first proposed by WHITFIELD DIFFIE of Stanford University in 1976. It transforms the message which is signed so that anyone who reads it can be sure of real sender. It is a message content called a message digest that represents a private. Encrypting a message digest with a private key creates a digital signature as explained in the next slide.

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Verification of a Digital SignatureVerification of a Digital Signature

1.The sender generates a message digest , encrypts it with 1.The sender generates a message digest , encrypts it with his private key and sends the digital signature to the his private key and sends the digital signature to the recipient along with the plain text message.recipient along with the plain text message.

2.The recipient uses the sender’s pubic key to decrypt the 2.The recipient uses the sender’s pubic key to decrypt the digital signature which authenticates that the message was digital signature which authenticates that the message was from the trusted sender .from the trusted sender .

3.The recipient uses “Hash function” to encode its own 3.The recipient uses “Hash function” to encode its own message digest of the sender’s text . message digest of the sender’s text . If the encoded If the encoded message turns out the same as one send by the message turns out the same as one send by the sender , the digital signature is considered to be sender , the digital signature is considered to be authentic and the message has not been tampered authentic and the message has not been tampered with with ..

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Digital SignaturesEach individual generates his own key pair

[Public key known to everyone & Private key only to the owner]

Private Key – Used for making digital signature

Public Key – Used to verify the digital signature

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Signed Messages

Message+

Signature

Message+

Signature

HashHash

DecryptSignatureWith Sender’s Public Key

DecryptSignatureWith Sender’s Public Key

SIGN hashWith Sender’s Private key

SIGN hashWith Sender’s Private key

Message+

signature

Message+

signature

COMPARECOMPARE

Calculated Hash

Calculated HashMessageMessage

Sender Receiver

HashHash

Signed Message

Sent thru’ Internet

if

OKSignatures

verified

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What does What does DigitalDigital Certificate Certificate contain?contain?

Owners name Owners public key Expiration date of the public key Name of the Certifying Authority Serial No. of digital certificate Duration and class of certificate Certificate ID number

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DIGITAL SIGNATURE DIGITAL SIGNATURE CERTIFICATES(DSC)CERTIFICATES(DSC)

1. A digital certificate is a electronic document issued by a Certificate Authority (CA) to establish a merchants identity by verifying its name and public key.

2. These are the electronic counter parts to drive licenses , passports and membership cards.3. One can present DSC electronically and prove ones identity or right to access information or services online.

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Classes of Digital Certificate Classes of Digital Certificate

Certificates can be issued (for a fee) in the following 4 classes:-

1.Class 1 certificates- Quickest and simplest to issue as they contain minimum checks on the user’s background. Only the name of the user, address, email address are checked

Example: Library Card.

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2. Class 2 certificates- Check for information like real name, social security

number and date of birth. It requires proof of physical address and email

Example: Credit Card

3. Class 3 certificates- Strongest types . It is used for loans acquired online and other sensitive transactions Example: Driving License

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4. Class 4 certificates- most secured business certificates. In addition to the class 3 requirements, the certificate authority checks on things like Users position in his/her organization.

NOTE:-

Considering the security in mind, Class 3 certificates and above are authorized by Ministry of Company Affairs 21 for online transactions

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Types and Status Services for Types and Status Services for Digital CertificateDigital Certificate

Certifying Authorities provide issuing, revocation and status services for following 3 types of digital certificates:

1. Server Certificates- Enable web servers to operate in a secure mode.

2. Developers Certificates- Used in conjunction with Microsoft Authenticode TM Technology, Provides customers with information and assurance they need when downloading software from the internet.

3. Personal Digital Certificates- Used by individuals when they exchange messages with other users or online services.

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IDRBT CertificatePaper Electronic

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BenefitsBenefits

1. Reliable authentication of messages2. Minimizes risk of dealing with imposters or persons who attempt to escape responsibility by claiming to have been impersonated3. Minimizing the risk of undetected message , tampering , forgery and of false claims that a message was altered after it was sent4. Formal legal requirements accepted as digital signatures are superior to writing a signature on paper5. Retaining a high degree of information security

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ChallengeChallengess

Digital signature involves the following costs:

1.Institutional Overhead- The cost of establishing and utilizing certification authorities, repositories and other important services, as well as assuring quality in the performance of their functions.

2.Subscriber and Relying Party cost-A digital signer will require software and has to pay Certifying Authority some price to issue a certificate.

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