Tutorial on using GnuPG (PGP) to encrypt information and digital signature (1)

PGP (Pretty Good Privacy) is a program developed by Phil Zimmermann in 1991 for data encryption and digital signature. It has been widely used to form an open standard OpenPGP, gnuPG is an open-source free program that implements this standard, this article will briefly introduce how to use GnuPG to manage keys, encrypt and decrypt files and emails, digital signature files, and emails. The length is a bit long, but the content is very simple. You can follow it step by step.

I. simple principles of encryption and digital signature

First, each person uses a program to generate a unique pair of keys on the earth, called the public key and private key respectively. The public key is used for encryption, and the private key is used for decryption. Information encrypted with the public key can only be unlocked by the paired private key.

The encryption process is: if Mr. A wants to send information to Mr. B, Mr. B must first throw his public key. Mr. A needs to obtain the public key of Mr. B and then encrypt the information and send it to him, B can use his private key to decrypt the received (encrypted) Information to restore the information.

The digital signature process is slightly different. The information is sent to the other party through normal unencrypted mode, but each piece of information is appended with a letter (Name: signature ), this signature is calculated by the program based on the sender's private key and information content. The receiver can use the sender's public key to check whether the information has been tampered.

2. obtain and install GnuPG

GnuPG is a tool that integrates key management, encryption and decryption, and digital signatures. For Linux systems, you can find GnuPG in the software source of the system, for example, you can run the following command to install ArchLinux:

$ Sudo pacman-S gnupg

For Windows systems, you can download the free open-source package GPG4Win. We recommend you download the full version, which includes both the GnuPG command line tool, the graphical key management tool Kleopatra, And the GnuPG-supported Mail client program Claws Mail.