Digital Signature

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Digital Signature

  1. 1. ITT CENTRE NAME: BIKANER BRANCH OF CIRC OF ICAI BATCH COMMENCEMENT DATE: 2ND DECEMBER 2013 PROJECT TOPIC: EXPAIN DIGITAL SIGNATURE WITH EXAMPLES. SUBMITTED BY: RAHUL YADAV CRO0428146 1
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  3. 3. This Is To Certify That MR. RAHUL YADAV Has Under Taken A Project On DIGITAL SIGNATURE WITH EXAMPLES . After Going Through The Report, We Wish To Record Our Satisfaction & Commend To MISS SONALI JAIN For The Effort Put In By Their In This Exercise. 3
  4. 4. DIGITAL SIGNATURE WITH EXAMPLES SUBMITTED BY RAHUL YADAV UNDER THE GUIDANCE OF MISS SONALI JAIN (I.T.T. FACULTY) Submitted In Partial Fulfillment For The I.T. Training Conducted By Bikaner Branch Of I.C.A.I For The Course Of I.P.C.C. BATCH NO. BIKANER-12/13/81 REG. NO. BKN/13-14/1607 4
  5. 5. While coming on acknowledgement, it seems to me closing of long chapter of reminiscences which bloomed and gloomed at BRANCH CHAIRMEN CA Rajiv Aeron, BIKANER BRANCH OF CIRC OF ICAI, BIKANER. This is my proud privilege to express my sincere and deep sense of gratitude my faculty member Ms. Sonali Jain for inspiration guidance, persistent involvement, scholarly suggestion and constructive critical supervision throughout the pursuit of present study. And finally many thanks to all those friends who kept company and who directly or indirectly helped me in the completing of this project work. RAHUL YADAV Submitted By :- Rahul Yadav ITT Reg. no. :- BKN/2013-14/1607
  6. 6. Submitted By :- Rahul Yadav ITT Reg. no. :- BKN/2013-14/1607 6
  7. 7.  Introduction  How they work  What is D.S Technology  Application  Why use..Reason  WYSIWUS  Public key Certificate  Digital Certificate  Why Digital Signature  Paper vs Digital Signature  Conclusion  Bibliography Submitted By :- Rahul Yadav ITT Reg. no. :- BKN/2013-14/1607 ….8-11 ..13-15 .…16 ……17 …18-23 …..24 …..25 .….26 …..27 ….28 ….29 …..30 7
  8. 8. A DIGITAL SIGNATURE is a mathematical scheme for demonstrating the authenticity of a digital message or document. 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(authentication and non-repudiation)and that the message was not altered in transit(integrity). Digital signatures are commonly used for software distribution, financial transactions, and in other cases where it is important to detect forgery or tampering. Submitted By :- Rahul Yadav ITT Reg. no. :- BKN/2013-14/1607 8
  9. 9. Digital signatures are often used to implement electronic signatures, a broader term that refers to any electronic data that carries the intent of a signature, but not all electronic signatures use digital signatures. In some countries, including the United States, India, and members of the European Union, electronic signatures have legal significance. For messages sent through a non secure channel, a properly implemented digital signature gives the receiver reason to believe the message was sent by the claimed sender. Digital signatures are more difficult to forge than the handwritten type. Digital signatures can also provide non-repudiation, meaning that the signer cannot successfully claim they did not sign a message. Submitted By :- Rahul Yadav ITT Reg. no. :- BKN/2013-14/1607 9
  10. 10. A digital signature scheme typically consists of three algorithms: A key generation algorithm that selects a private key uniformly at random from a set of possible private keys. The algorithm outputs the private key and a corresponding public key.  A signing algorithm that, given a message and a private key, produces a signature.  A signature verifying algorithm that, given a message, public key and a signature, either accepts or rejects the message's Submitted By :- Rahul Yadav ITT Reg. no. :- BKN/2013-14/1607 10
  11. 11. In 1976, Whitfield Diffie and Martin Hellman first described the notion of a digital signature scheme, although they only conjectured that such schemes existed. Soon afterwards, Ronald Rivest, Adi Shamir, and Len Adleman invented the RSA algorithm, which could be used to produce primitive digital signatures. . The first widely marketed software Submitted package to offer digital no. :-By :- Rahul Yadav was Lotus Notes signature ITT Reg. BKN/2013-14/1607 11
  12. 12. Submitted By :- Rahul Yadav ITT Reg. no. :- BKN/2013-14/1607 12
  13. 13. BOB Private key(d) ORIGINAL PLAIN TEXT Dear Alice—The Meeting Will be Held in Embassy Decryption function CIPHERTEXT Qrne cliae– Gur zasder bh ke measy Encryption function PLAIN TEXT Dear Alice– The Meeting Will be Held in Embassy .  No Secret key is ever exchanged.  Alice does not need her own key to use the system. Submitted By :- Rahul Yadav ITT Reg. no. :- BKN/2013-14/1607 ALICE Public key(e,n) 13
  14. 14. I Hereby Give You A Raise I Hereby Give You A Raise. 192 2343 9102 Private (d) BOB Encrypt with the Private Key Attach to the end of the original message. I Hereby Give You A Raise. I Hereby Give You A Raise. Public (e,n) Decrypt with the Public Key Authenticate by Comparing to Plaintext Message Submitted By :- Rahul Yadav ITT Reg. no. :- BKN/2013-14/1607 ALICE 14
  15. 15. I Hereby Give You A Raise. I Hereby Give You A Raise 192 2343 9102 Evil Faked BOB Evil Haye ahge kae gakg. Public (e,n) Signature does not Match Message=> Message not Authenticated Submitted By :- Rahul Yadav ITT Reg. no. :- BKN/2013-14/1607 I Hereby Give You A Raise. ALICE 15
  16. 16. What is Digital Signature Technology…?? Generating message’s digest (hash result) Using Public Key to encrypt hash result Result of the encryption: digital signature Sender sends message, digital signature and certificate to receiver Receiver wants to check Integrity :-Generating hash result, compare it to the sender’s hash result and decrypting the message with the sender’s Submitted By :- Rahul Yadav 16 public key ITT Reg. no. :- BKN/2013-14/1607
  17. 17. Authentication :Although messages may often include information about the entity sending a message, that information may not be accurate. Digital signatures can be used to authenticate the source of messages. The importance of high confidence in sender authenticity is especially obvious in a financial context. For example, suppose a bank's branch office sends instructions to the central office requesting a change in the balance of an account. If the central office is not convinced that such a message is truly sent from an authorized source, acting on such a request could be a grave mistake. Submitted By :- Rahul Yadav ITT Reg. no. :- BKN/2013-14/1607 17
  18. 18. How do we do this if the Document is Digital and Not Paper..? Submitted By :- Rahul Yadav ITT Reg. no. :- BKN/2013-14/1607 18
  19. 19. This can be Forged easliy…! Graphic file Has this Email Signed..? Submitted By :- Rahul Yadav ITT Reg. no. :- BKN/2013-14/1607 19
  20. 20. A True Signature:  Is Authentic.  Cannot be Forged.  Cannot be Refused.  Proves document has not been Altered.  Cannot be Repudiated. Submitted By :- Rahul Yadav ITT Reg. no. :- BKN/2013-14/1607 20
  21. 21. In many scenarios, the sender and receiver of a message may have a need for confidence that the message has not been altered during transmission. Although encryption hides the contents of a message, it may be possible to change an encrypted message without understanding it. However, if a message is digitally signed, any change in the message after signature invalidates the signature. Furthermore, there is no efficient way to modify a message and its signature to produce a new message with a valid signature. Submitted By :- Rahul Yadav ITT Reg. no. :- BKN/2013-14/1607 21
  22. 22. Non-repudiation :- Non-repudiation, or more specifically nonrepudiation of origin, is an important aspect of digital signatures. By this property, an entity that has signed some information Documents cannot at a later time deny having signed it. . Checking revocation status requires an "online" check, e.g. checking Very roughly this is analogous to a vendor who receives creditcards first checking online with the creditcard issuer to find if a given card has been reported lost or stolen. Submitted By :- Rahul Yadav ITT Reg. no. :- BKN/2013-14/1607 22
  23. 23. In order to be semantically interpreted, the bit string must be transformed into a form that is meaningful for humans and applications, and this is done through a combination of hardware and software based processes on a computer system. WYSIWYS means that the semantic interpretation of a signed message cannot be changed. In particular this also means that a message cannot contain hidden information that the signer is unaware of, and that can be Submitted By :- Rahul Yadav revealed after the signature has been applied. 23 ITT Reg. no. :- BKN/2013-14/1607
  24. 24. A public key certificate (also known as a digital certificate) is an electronic document that uses a digital signature to bind a public key with an identity — information such as the name of a person or an organization, their address, and so forth. In a typical public key infrastructure (PKI) scheme, the signature will be of a certificate authority (CA). There are Three Companies in INDIA which certified the Digital Signature:- 1). Infosys 2). Wipro 3). TCS Submitted By :- Rahul Yadav ITT Reg. no. :- BKN/2013-14/1607 24
  25. 25. A Digital Certificate is issued by a Certification Authority (CA) and signed with the CA's private key. A Digital Certificate typically contains the:  Owner's public key  Owner's name  Expiration date of the public key  Name of the issuer (the CA that issued the Digital Certificate)  Serial number of the Digital Certificate  Digital signature of the issuer Submitted By :- Rahul Yadav ITT Reg. no. :- BKN/2013-14/1607 25
  26. 26. Authentication, Integrity, Low cost, Eliminates the use of paper, Faster Procedures, Completely Secure. Submitted By :- Rahul Yadav ITT Reg. no. :- BKN/2013-14/1607 26
  27. 27. PARAMETER DIGITAL PAPER Authenticity May be Forged. Can not be Forged. Integrity Signature independent of the Document. Signature depends on the contents of the documents. Non- Repudiation a. b. a. b. Handwriting expert needed. Error prone. Submitted By :- Rahul Yadav ITT Reg. no. :- BKN/2013-14/1607 Any computer user. Error free. 27
  28. 28. Digital signatures are a valuable technology for every major corporation. Combined with RSAand PKI for certificate lifecycle management digital signatures can speed up business processes. It as well supports any other security application based on digital certificates. For instance, Virtual Private Networks, e-mail encryption, and secure WWW portals can be realized with the digital certificates provided by RSA and PKI. The more applications a PKI is used for, the more economic it gets. Submitted By :- Rahul Yadav ITT Reg. no. :- BKN/2013-14/1607 28
  29. 29. My Creativity My Efforts MISS SONALI JAIN ITT MODULES Submitted By :- Rahul Yadav ITT Reg. no. :- BKN/2013-14/1607 My Hard Work 29
  30. 30. Submitted By :- Rahul Yadav ITT Reg. no. :- BKN/2013-14/1607 30

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