Encryption means to scramble a message in such a way that only the people who are meant to read it can do so.
A message sent 'in the clear' looks like:
"This is a message anyone can read"
and the encrypted message looks like gibberish:
Encryption works by both people making use of a secret 'key' that only they know (or at least their computers know). The original message is mixed in with the key to create a secret message. This is done by some very crafty mathematics so that it is very very hard for someone to crack the code - very powerful computers working for a long time would be needed to crack a good code.
Challenge see if you can find out one extra fact on this topic that we haven't already told you
Click on this link: Encryption