digital signiture
TRANSCRIPT
A SEMINAR ON
PRESENTED BY :
•VikeshBawane
• Abinesh Tandra
•Venkatesh Asampelli
• Shiv Prakash ReddyH. O. D.
Mrs. S.S. Bhaskarwar
GUIDED BY :
Mrs. Priyanka Singh
INCHARGE:
Mrs. Priyanka Balki
WHAT IS CRYPTOGRAPHY ?
Science of using mathematics to encrypt and decrypt data .
Science of securing data .
KEYS :
Value that works with a cryptographic algorithm to produce a specific cipher text
There are two keys :Private key
Public key
ENCRYPTIONEncryption is the
process of feeding plaintext and key into a function and getting cipher-text output
Cipher-text is “garbage” unless decrypted
© Yingjiu Li 2007 4
EncryptionFunction
Plaintext
© Yingjiu Li 2007 5
DECRYPTIONDecryption is the
process of feeding cipher-text and a key into another function and getting original plaintext output
DecryptionFunction
Plaintext
What is Digital Signature?• Hash value of a message when
encrypted with the private key of a person is his digital signature on that e-Document– Digital Signature of a person
therefore varies from document to document thus ensuring authenticity of each word of that document.
– As the private key of the signer is known, anybody can verify the message and the digital signature
•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
Concepts
• A 1024 bits number is a very big number much bigger than the total number of electrons in whole world.
• Trillions of Trillions of pairs of numbers exist in this range with each pair having following property– A message encrypted with one element of the
pair can be decrypted ONLY by the other element of the same pair
• Two numbers of a pair are called keys, the Public Key & the Private Key. User himself generates his own key pair on his computer
• Any message irrespective of its length can be compressed or abridged uniquely into a smaller length message called the Digest or the Hash.
• Smallest change in the message will change the Hash value
Digital Signature Digital Signature
Hash Hash Function Function
MessageMessage
SignatureSignature
Public KeyPublic Key EncryptionEncryption
DigestDigest
MessaMessagege
DecryptionDecryption
Private KeyPrivate Key
ExpectedExpectedDigestDigest
ActualActualDigestDigest
SignerSigner ReceiverReceiverChannChannelel
DigestDigestAlgorithmAlgorithm
Modules
Assign Digital signature Encryption & Decryption
to document of data using RSA
algorithm:- 1.Key
generation
2.Encryption
3.Decryption
Challenges and OpportunitiesOpportunities:-Imposters: by minimizing the risk of
dealing with imposters or persons who attempt to escape responsibility by claiming to have been impersonated;
Message Integrity: by minimizing the risk of undetected message tampering and forgery, and of false claims that a message was altered after it was sent;
Formal legal Requirements: by strengthening the view that legal requirements of form, such as writing, signature, and an original document, are satisfied, since digital signatures are functionally on a par with, or superior to paper forms; and
CHALLENGES AND OPPORTUNITIES CONT’D
Opportunities:-Open Systems: by retaining a high
degree of information security, even for information sent over open, insecure, but inexpensive and widely used channels.
Advantages Data integrity
Authentication of Identities
Non-repudiation
date and time stamp
speed and accuracy
APPLICATIONTo certify a document with digital
signature.
For securing data transaction between the parties.
It will use in a large scale organization for mutual
agreement.
To transmit secure data.