A digital signature is a mathematical scheme that demonstrates the authenticity of a digital message or document. It provides recipients reason to believe that the message was created by a known sender and was not altered in transit. Digital signatures can authenticate the source of messages, ensure integrity so messages are not altered, and provide non-repudiation so senders cannot deny having sent messages. They use public and private key cryptography where the private key is kept secret by the sender.

1. A Digital Signature Is A
Mathematical Scheme For
Demonstrating The
Authenticity Of A Digital
Message Or Document
Prepared by Tejashree Bangera

2. .
A Valid Digital Signature gives a
Recipient
Reason to believe that the Message
was created by a Known Sender,
such that the Sender cannot
Deny having sent the Message
and that the Message was not
Altered in Transit

3. Uses
Usesὄ Authentication- Digital signatures can
be used to authenticate the source of
messages.
ὄ Integrity- , the sender and receiver of a
message may have a need for
confidence that the message has not
been altered during transmission
ὄ Non-repudiation- By this property, an
entity that has signed some information
cannot at a later time deny having
signed it.

4. SACHIN
SACHIN’S PUBLIC KEY
SACHIN’S PRIVATE KEY
Anyone can get
Sachin’s Public
Key, but He
keeps his
Private Key to
himself
ROHIT VIRAT DHONI

5. ROHIT can encrypt a message using SACHIN's Public Key.
SACHIN's uses his Private Key to decrypt the message.
Any of SACHIN's Friends might have access to the
message ROHIT encrypted, but without Sachin’s Private
Key, the data is worthless.
"Hey Sachin,
how about a
game at the
Eden Garden. I
hear they have
free entry!"
HNFmsEm6Un
BejhhyCGKOK
JUxhiygSBCEiC
0QYIh/Hn3xgiK
BcyLK1UcYiY
lxx2lCFHDC/A
HNFmsEm6Un
BejhhyCGKOK
JUxhiygSBCEiC
0QYIh/Hn3xgiK
BcyLK1UcYiY
lxx2lCFHDC/A
"Hey Sachin,
how about a
game at the
Eden Garden.
I hear they
have free
entry!"

7. Sachin now passes the document on to Dhoni.

8. AdvantagesAuthenticates Your Identity Electronically
Provides You With A High Level Of Security For Your Online Transactions
Absolute Privacy Of The Information Exchanged Using A Digital Certificate.
Use Certificates To Encrypt Information Such That Only The Intended Recipient Can
Read It.
You Can Digitally Sign Information To Assure The Recipient That It Has Not Been
Changed In Transit
Verifies Your Identity As The Sender Of The Message`
For Secure Email And Web-Based Transactions, Or To Identify Other Participants
Of Web-Based Transactions
To Prove Ownership Of A Domain Name And Establish SSL/ TLS Encrypted Secured
Sessions Between Your Website And The User For Web Based Transactions
As A Developer, For Proving Authorship Of A Code And Retaining Integrity Of The
Distributed Software Programs
For Signing Web Forms, E-Tendering Documents, Filing Income Tax Returns,
To Access Membership-Based Websites Automatically
Without Entering A User Name And Password Etc.

9. News!!! News!!!
Birth and death certificates issued by BMC could
soon be signed by the health officers concerned
through digital signatures if a proposal passed on
to the administration is passed
The digital signatures will be password-protected
and health officers can approve applications
online at a convenient time, making it possible to
authorise applications faster.

11. ENTIRE OBJECT SIGNATURES
This Type Of Signature Includes All But A Few
Nonessential Bytes Of The Object.
CORE OBJECT SIGNATURES
This Type Of Signature Includes The Essential
Bytes Of The *CMD Object. However, The
Signature Does Not Include Those Bytes That
Are Subject To More Frequent Changes. This
Type Of Signature Allows Some Changes To Be
Made To The Command Without Invalidating
The Signature.
TYPES OF DIGITAL SIGNATURES

12. Misuse Of Trusted Time
Stamping- Since Automated Date Is Included,
The Reader Cannot Be Certain That The Signer Did
Not Backdate The Date And Time Of The Signature.
Non-Repudiation-Even If The User Wants To
Make Changes To A Signed Document Then Alteration Will
Make It Invalid. Hence A New Message Has To Be Drafted.
Disadvantages

13. IDRBT Certificate
Paper Electronic

14.  Digital Signatures depend on a digital object, hence they
are susceptible to fraud.
 And reliability includes more than authenticity and
integrity.
 Accuracy and trust also play an important role in the
authentication of records.
 However, due to this new technology, there is an
introduction of online file movement system, e-
commerce, online money orders, and even E-voting might
be the next step in future.
Assurance of Reliability is a never ending
process that starts on the creation or receipt ,
and must be maintained during the entire life
cycle.