3. Confidentiality of LDAP exchanges

Encryption techniques have been around for almost 4,000 years. The general principle is to transform the content of a message using either a secret algorithm, or a publicly known algorithm involving a secret key, in such a way that the transmitted message can only be read by the recipient.

Nowadays, thanks to computers, it's easy to encrypt messages using algorithms that are more complex and reliable than so-called "classical" methods. The first techniques used were based on the notion of symmetrical keys. The key used to encrypt a message is also the key used to decrypt it.