# Asymmetric Encryption

Asymmetric encryption (sometimes called public key encryption) is a form of encryption where a pair of keys are responsible for encrypting and decrypting data.

This is different to symmetric encryption where the same key is used to encrypt and decrypt.

**Asymmetric encryption uses a special pairing of keys:**

**Public key**– anyone can ask for a copy**Private key**– remains private on the computer, never sent- Both needed to decrypt
- Only public key is needed to encrypt

Because both keys are needed to decrypt, it doesn’t matter who sees the public key – all they can do is encrypt data with it!

**SSL uses a combination of symmetric and asymmetric encryption where:**

- Asymmetric encryption resolves the key distribution problem, so that
- Data can be transmitted using symmetric encryption

**Example process:**

- A symmetric key is encrypted by the sending computer using the public key sent by the receiving computer (usually via SSL certificate)
- The encrypted symmetric key is sent to the receiving computer (unreadable if intercepted)
- Using the stored private key, and the readily available public key, the receiving computer decrypts the symmetic key
- Now, both computers have the same symmetric key ready for secure encrypted data transmission