Public Key Authentication

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Revision as of 01:47, 5 April 2009 by Larocqt (Talk)
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Public key authentication is a process of information cryptography that involves the use of public and private keys.

  • also known as asymmetric authentication
  • cryptography
  • key pair (public key/private key)
  • private key only exists on source system and generates signatures which cannot be forged
    • anyone possessing matching public key can verify the signature
  • public key can be used to encrypt messages for the source system
    • only the system possessing the matching private key can decrypt the message

Contents

Background

  • briefly explain password-based/symmetric key authentication
  • go in more detail on public key authentication

Identity Verification Process

  • Generate a key pair on your computer
  • Copy your public key to the server
  • When authentication is required, a signature is generated using the private key
  • Server uses the public key to verify the signature and grant access

Message Encryption/Decryption Process

  • Generate a key pair on your computer
  • Send your public key to the desired user you wish to communicate with
    • Recipient may generate their own key pair
  • Sender uses the recipient's public key to encrypt the message and sends it
  • Recipient uses their private key to decrypt the message

Physical World Equivalent

  • padlock, lockbox, keep their key

Benefits

  • if server is hacked/spoofed
    • attacker can learn your password in symmetric key authentication
    • attacker would still need your private key in asymmetric key

Drawbacks

  • computational cost
    • explain uses of hybrids

Public Key Algorithms

  • RSA Algorithm
  • DSA/DSS (Digital Signature Standard) Algorithm
  • Diffie-Hellman Algorithm

References

  • [1] - Using Public Key Authentication
  • [2] - Public Key Cryptography

See Also

External Links

--larocqt 9:23 PM, 4 April 2009 (EDT)

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