Security precautions
Use of Public and Private Keys
Data transmitted over the Internet is very easy to intercept and most of it is text based.
In order to keep data secure in transit it is encryptionScrambling a message using a secret method (known as a cypher) so that only the sender and recipient (who know the cypher) can decode and read the message.. A process, called a cypherThe process of encrypting a message., is used to scramble the data so that it doesn’t make sense. The cypher is reversible so the original message can be restored if you know the cypher.
An encryption key specifies how the cypher scrambles data and how to turn this back to the original data.
To be secure, the system sending data and the system receiving it must agree on a key that no one else knows. Both systems need to know what the key is without transmitting the key itself. Otherwise anyone intercepting the encrypted message also knows the key.
Public-key encryption (PKE) solves this problem by using two keys.
The two keys are mathematically linked, normally generated from a large, random number.
- Public key - known by everyone and is used to encrypt the message.
- Private key - known only by the recipient and is used to decrypt the message.
- Cyphers are very complex - only the private key can decrypt the message.
- The public key cannot be used to work out the private key.
