Public Key

A Public Key is a public string used in a public-key cryptography system.

• Context:
  • It can be used to encrypt Plaintext.
  • It can be used to verify a Digital Signature.
  • It can (often) be stored in a Public Key File (such as id rsa.pub).
• Example(s):
  • an RSA v2 Public Key.
  • …
• Counter-Example(s):
  • a Private Key.
• See: SSH Protocol, RSA.

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References

2013

• http://en.wikipedia.org/wiki/Public-key_cryptography
  • … The public key is used to encrypt plaintext or to verify a digital signature; whereas the private key is used to decrypt ciphertext or to create a digital signature. … It is computationally easy for a user to generate his or her public and private key-pair and to use them for encryption and decryption. The strength lies in the fact that it is "impossible" (computationally infeasible) for a properly generated private key to be determined from its corresponding public key. Thus the public key may be published without compromising security, whereas the private key must not be revealed to anyone not authorized to read messages or perform digital signatures.

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