How PGP Works: Messages
Signing a message: pgp -sat file
- Compute a Message Digest (hash) of the message (MD5)
- Encrypt the hash with the signer's Private Key
Encrypting a Message: pgp -ea file recipient(s)
- Compress the file
- Choose a Random Secret (IDEA) Key (session key)
- Encrypt message in IDEA using session key
- Encrypt session key in recipients' Public Key(s)
Sign and Encrypt a Message: pgp -sea file recipient(s)
- Generate a signature on the file, as above
- Encrypt the signature and file, as above
Verifying a Message: pgp file
- Decrypt session key using Private Key
- Decrypt message using session key
- Generate Message Digest of the message
- Decrypt signature using signer's Public Key and compare
Ascii Armor: -a
- Takes a PGP message and wraps it in ASCII, so it can be transmitted
over mail or printed.
- Is _only_ a wrapper; the armor is not secured.
Next: Key Management