Email tips -> How to send secret emails by encrypting emails

There is always a danger that your emails are snatched on their way and be read. Luckily there are ways that you can use to make these emails unreadable by others on the way. In this article we shall see methods to secure your emails by encrypting them.

Assume that Jack is sending an email to Stella. This email can be read by anyone who has access to this email on the way. If Jack wants that no one else other than Stella should be able to read this email then what can he do? Here's where public key and private key can come to the rescue.

What is public Key and Private Key?

Here KEY is referred to the string made of 0s and 1s. There are 64bit, 128bit and 256bit keys. A 64bit key means that it contains a combination of 64 0s and 1s.

If the number of bits in a key is more then it is more difficult to crack it. Each one has to create a public key and a private key and inform other s about the public key. The private key should not be revealed to anyone else.

A readable text is called 'clear text' or 'plain text'. To make this message unreadable you have to encrypt it using your public key or the private key. This encrypted text is then called 'cyber text'. So 'clear text' is encrypted to make a 'cyber text'.

To convert the encrypted text back to its readable form is called 'decryption'. In order to decrypt you should use one's public key or the private key. It should be noted that a message that was encrypted using public key can only be decrypted using its private key. And the message that was encrypted using the private key has to be decrypted using its corresponding public key. So a person's public key and private keys are pairs and has to be used in pair.

How will we know the public key of someone?

We can send our public key to others through email. Or you may want to publish it in your personal website for your friends to see. You may even print your public key in your name card. You can also publish your public key in a 'Public Key Directory'.

To confirm the recipient of the email.

Let us go back to the same example. When Jack composes an email he will use the public key of Stella to encrypt the message. Then he will send this cyber text(encrypted email) via internet to Stella. If someone gets this message in between he cannot read this message as it is encrypted. The reason is because the message is encrypted using Stella's public key. So this message is readable only if it is decrypted. To decrypt this message Stella's Private key is required. Only Stella knows her private key. So others cannot read this message.

In this method the recipient is confirmed because only Stella can read this message. But how to find that this message is from Jack and not anybody else. To confirm the sender follow the method as described below.

To confirm the Sender

If Jack creates an email and encrypts the message using his private key and encrypts the message and sends it to Stella. So whoever knows Jack's public key can decrypt this message and read it.

By this method the sender of the message is confirmed as Jack. But not only Stella, any others who knows jack's public key can decrypt the message. In this method therefore the recipient is not secured only the sender is confirmed.

To secure both the sender and recipient.

In both the methods discussed above the message is encrypted only once. If instead the message is encrypted twice then both the sender and recipient can be confirmed.

So to achieve this, Jack should encrypt the message using his Private key first. After that he has to encrypt again using Stella's Public Key and then send it to Stella.

By this method only Stella can decrypt the message fully and read it