Digital signature Algorithm for cryptography.ppt

Digital signature Algorithm for cryptography.ppt

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  1 Digital Signature Visit formore Learning Resources
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  Digital Signature • 1.Digital Signature is a type of electronic signature that encrypts documents with digital codes that are particularly difficult to duplicate • 2. In case of digital signature message is encrypted with the private key and decrypted with the public key.
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  On BOB
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  On FRANK side
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  Digital Signature Algorithm 7
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  At Sender Side •1.Message digest is generated using a set of Hash functions. •2. A message digest is encrypted using senders private key. •3. The resulting encrypted message is known as digital signature. •4. Digital signature is attached with data or message and send to receiver.
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  At Receiver Side 1.Receiver uses senders public key to decrypt senders digital signature to obtain message digest send by receiver. 2. Receiver uses same message digest algorithm, which is used by sender 3. Now, receiver will compare these two message digest 4. If message digest are equal then signature is valid else not.
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  Advantages • Authentication: – Identificationof person sign. • Integrity of data: – Every change is detected. • Non Repudiation: – Author has encrypted sign on message. • Speed: – Contracts are easily written, completed, and signed by all concerned parties in a little amount of time no matter how far the parties are geographically.
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  Disadvantages • Expiry • Certificateissue procedures • Software compatibility