satya - Monday, March 15, 2010 10:36:50 PM

Excellent article on the subject from Sun

satya - Monday, March 15, 2010 10:41:49 PM

public private keys

satya - Monday, March 15, 2010 10:43:14 PM

wikipedia is a good place to start

satya - Monday, March 15, 2010 10:45:01 PM

Internet standards that use public key cryptography


TLS - Transport Layer Security (replacing SSL)
PGP
GPG

satya - Monday, March 15, 2010 10:46:16 PM

A user intending to encrypt has two keys


private key - the one used to encrypt
public key - key that everyone knows how to decrypt

satya - Monday, March 15, 2010 10:50:00 PM

Only...

There is only one public key that can decrypt the message encrypted by the private key. Everyone knows the public key. For example if you were to receive an encrypted message and if you have many public keys with you, you will be able to decrypt (if you could) it with ONE and ONLY ONE public key. If you know who gave you that public key then you know who sent it unequivocally. This is the secret of public and private keys

They come in pairs. They allow a receiver to know exactly who sent the message. when ever you are in need of such a functionality think of public/private keys.

You can use the java tool called "keytool" to generate these public/private keys.

satya - Monday, March 15, 2010 10:53:32 PM

Public key/Private keys are called asymetric

They are computationally intensive. If you have a lot of data to encrypt and decrypt you may want to encrypt a symmetric key first with public/prviatekey combination and then encrypt the rest with the symmetric key.