I've been looking at the idea of encryption of traffic over the internet, just finished reading a lot of articles on how public key encryption works.
Here is what I understand so far:
1. Large random number is generated, from this a private and public key is generated
2. The Public key is freely available to anyone
3. If someone wants to send a message to a person using private key encryption then they encrypt things with the public key, send them then they are decrypted using the private key
I know that that is a very simplistic view of how things work but I have one problem with it:
What is to stop someone simply 'going backwards' in terms of the encryption process, for example if I encrypt something using a public key why can't I simply decrypt it using the same public key?
An answer to this would be greatly appreciated as I am quite confused as to how this would work.