posted 14 years ago
Hi!
As far as I understand, you can encrypt data using either the public or private key, as long as you use the other, that is the private or public key, to decrypt the data.
The most common case is encryption using the public key, which is freely distributed. The encrypted data can then only be decrypted by the party that holds the private key, which is supposed to be a well-kept secret.
With signing of data only one party is supposed to be able to produce a signature of some data while anyone is supposed to verify from where the signature came. Thus, the private key is used to sign the data and the public key can then be used to verify the signature.
Best wishes!