Description: Are you threatened that once you lost your email account, and the thief uses your email to phish your friends. Your friends might think that email comes from you and give the thief the information that he wants. That's terrible.
Or another case, you send to your friends some sensitive data. And one day, he/she lost the email. The thief can read all that information.
Is there any solution to prevent those cases? Yes, there are a lot. Once of them is encryption. With the normal encryption, you and your firends must own the same key to read the message. And that key, both you and your friends must keep them in safe place. If one of you lose the key. The thief can read the message.
Now I will introduce to you a new way of protecting your email message. The "Message Protector" application. Every one will have a pair of keys to protect yourself: public key and private key.
Public key: you can give it to anyone that will receive you message. This key can help you to confirm with your friends that, this message is created by you. Moreover, with this key, if your friends send you a message, only one you the one who has the private key can read the message.
Private key: this is your personal secret key. Please keep it safe. You can use this key to create a message which is confirmed that it is created by yourself. And if your friends use your public key to create a message to you, you are the only one can read the message.
Is this wonderful? How to do that? Have you ever know that there is a agorithm of encryption called RSA? It was applied in the application with a little bit of changes