1. INTRODUCTIONPretty Good Privacy, known as PGP, is a popular data encryption and decryption program, which provides security services for email messages and data files. Created by Philip Zimmermann in 1991, this program has been widely used in the global computing community to protect the confidentiality and integrity of users' data by granting them the privacy to deliver messages and files only to the designated or authorized person (Singh, 2012) . Not only being useful to individuals as a privacy program, it has also been used in many businesses to protect their company's data from falling into the wrong hands (Rouse, 2005). This program mainly uses the concept of encryption. Cryptography is the study of secret communication between two parties, where there is the presence of a third party known as adversaries, and that party knows nothing about the content of the communication (Rivest, 1990). The security that PGP offers is basically based on the concept of encryption and decryption, touching on different types of keys such as public keys and conventional keys, hash function, digital signatures and sometimes a combination of some methods to make sending data to users even more secure. right and authorized recipients. Furthermore, following the Internet Standard Track, this program is currently one of the widely used reliable programs (Stallings, 2011).2. ENCRYPTION IN THE PRETTY GOOD PRIVACY PROGRAM 2.1 Cryptology Generally, the Pretty Good Privacy Program (PGP) is all about cryptography, with encryption and decryption at its core. Encryption is a process of encoding the message, to the extent that the meaning of the message is not obvious or cannot be read... in the middle of the card... hey, so the more random the keystrokes, the better the data needed to generate the key (Senderek, 2003).2.2.4 Passphrase-based symmetric keysThe passphrase is very similar to the password, except that it is a longer version of a password and is theoretically more secure than the password (Network Associates, Inc., 1999). It is a secure code created with one or a few words chosen by the user for a security setting (Mitchell, n.d.). Normally, for a passphrase, it contains multiple words, where the words may or may not be found in a dictionary. A good passphrase is similar to a good password, and the characteristics of a good passphrase should be long and complex, containing uppercase and lowercase letters, symbols and numbers. Therefore, it is obviously more secure than the password, where the attacker tried all the words to figure out the passphrase used.