Cryptography

What is symmetric 

encryption? 

What is Symmetric Encryption?

Symmetric Encryption (or pre-shared key encryption) uses a single key to both encrypt and decrypt data. Both the sender and the receiver need the same key to communicate. Symmetric key sizes are typically 128 or 256 bits—the larger the key size, the harder the key is to crack.

For example, a 128-bit key has 340,282,366,920,938,463,463,374,607,431,768,211,456 encryption code possibilities. As you can imagine, a ‘brute force’ attack (in which an attacker tries every possible key until they find the right one) would take quite a bit of time to break a 128-bit key. Whether a 128-bit or 256-bit key is used depends on the encryption capabilities of both the server and the client software. TLS/SSL certificates do not dictate what key size is used.