Decrypting a Message with PGP

signature

}

Encrypted session

key plus encrypted

message

Decrypt using

IDEA

Decrypt one-time

session key using

RSA

Alice

receiver’s private key

Decrypted,compressed

message, with or without

signature

receiver's public

key ring

Encrypt session

key using RSA

Receiver supplies

pass phrase

key ID attached

to session key

one-time session key

step1: PGP will fetch the receiver's private key from private key ring

using the Key ID in the session key component of the message .

step2: PGP prompts the user for pass phrase to recover the recipient's

private key.

step3: PGP then recovers the session key and decrypts the message.