What are encrypted emails and how do PGP and S/MIME technologies work in email?

Standard email transmits messages in plain text by default, making them vulnerable to interception by providers, server administrators, or malicious actors. To ensure confidentiality, end-to-end encryption and special cryptographic protocols are used, among which PGP and S/MIME are the most popular. These technologies guarantee that only the final recipient with the corresponding private key can read the email.

The PGP protocol is based on asymmetric cryptography, where each user has a pair of keys: public and private. The public key can be freely distributed among interlocutors to encrypt messages sent to you, while the private key is kept strictly secret and used exclusively for decrypting incoming mail. This approach allows you to fully control the security of correspondence without trusting third-party mail services.

S/MIME technology works in a similar way, but uses digital certificates issued by accredited certification authorities. This makes integration more convenient in a corporate environment, where trust between employees and partners is built based on the organization's certificate hierarchy. In addition, S/MIME is supported "out of the box" in many popular desktop and mobile mail clients.

Setting up encryption requires certain technical skills and attention to detail. If a user loses their private key or the password to it, restoring access to encrypted email archives will become technically impossible. Therefore, the process of generating keys and backing them up must be performed with maximum responsibility and compliance with information security rules.