Concepts

What is encryption?

Encryption is the process of transforming the original data (“plain text”) into something unreadable by the third party. If you want to see this content (decrypt it) you need a key, that was used to encrypt.
If you don’t have it – you cannot see the content

Types of encryption

Basically there are two Encryption techniques:

  • Symmetric Encryption
  • Asymmetric Encryption

Symmetric encryption

In symmetric encryption only one key is used. That key is used to encrypt and decrypt data. So, you have some data that you want to encrypt. You specify the key (password) and your data is encrypted using this key. Then, if you want to see the contents (decrypt it) you enter the same key and your data is decrypted.

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If you don’t know the key obviously that you won’t be able to decrypt the message
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So, in this technique the only thing you need to worry about is your key. Nowadays there are lot of available tools that can be used to protect your encryption key. Finally, you can just remember it and keep it in your memory.

Symmetric encryption is good and simple, but has one major issue – secure data exchange. Imagine that you want to send protected message to your friend. You encrypt it using your key and send it to your friend. So, your friend receives it and wants to see the original content. But he can’t because he doesn’t know the key.

So, if you want your friend to read your message, you need to send him a key. And this is problem – how to send this key that nobody can intercept it? Of course there are some ways to do it like HTTPs or just calling your friend and asked him to write the key. But still it is complicated (especially for non-technical people) and not convenient. You have to do a lot of things before sending protected message. Sometimes it’s not worth it

Asymmetric Encryption

Asymmetric Encryption was the answer to these problems. So, instead of one key we have two keys – public and private. These keys are generated together and bound to each other using complicated math

So, let’s see how the asymmetric encryption can be used to exchange protected messages. Suppose Batman wants to send the encrypted message to Jim Gordon.

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Here are the steps to do it.

  1. Batman asks Jim to send his public key. Public key can be sent via public internet without any precautions. This is why it’s called public
  2. Jim sends Batman his public key
  3. Batman creates a message and encrypts it using Jim’s public key. So, Batman is using Jim’s public key as the password to encrypt his message
  4. Then Batman sends this message over public internet to Jim
  5. Jim receives the message and wants to see its contents
  6. The only way he can do it is using his Private key. Remember, that public and private keys are always generated together and bound to each other
  7. Jim uses his Private key to decrypt and read Batman’s message
  8. Then if Jim wants to send protected message back to Batman, he just asks Batman to send his public key and encrypts the message using his Public key. Then Batman can decrypt this message using his Private key

The strongest point about Asymmetric encryption is that Private key (used to decrypt the messages) never leaves your PC, so it cannot be intercepted by anyone. So Batman and Jim can exchange messages securely via public channel. So, the only thing they need to worry about is their private keys. But modern OS made this task is even easier by providing built-in protection modules. To provide even better protection, you can use various 3rd party tools

But, of course this level of security comes at some cost. Asymmetric encryption is much more complicated than symmetric. For non-technical (but sometimes ever for technical) people it will very hard to understand and implement this in your daily routines

See the What is Saferoom? section to find out how Saferoom can be used to protect your data.