Most Unicies (and Linux is no exception) primarily use a one-way encryption algorithm, called DES (Data Encryption Standard) to encrypt your passwords. This encrypted password is then stored in (typically) /etc/passwd (or less commonly) /etc/shadow.

Does Linux have encryption?

Most Linux distributions mainly use a one-way encryption algorithm, which is called Data Encryption Standard (DES) for encrypting passwords. These encrypted passwords are then stored typically in /etc/passwd or in /etc/shadow but this is less commonly.

How secure is Linux encryption?

Yes, it is secure. Ubuntu uses AES-256 to encrypt the disk volume and has a cypher feedback to help protect it from frequency attacks and others attacks that target statically encrypted data. As an algorithm, AES is secure and this has been proved by crypt-analysis testing.