End-to-end Encryption and How it Works


Social networks, like Facebook, and messaging apps, like Chat, have become increasingly vulnerable in recent years, leading to the rise of end-to-end encryption (E2EE) to protect communication. Platforms such as WhatsApp, Signal, and Telegram use end-to-end encryption to protect the exchange of user data. Through this article, we will try to get a better understanding of what it means to say ‘end-to-end’, and what are its benefits and drawbacks.

What Does End-To-End Encryption Mean?

What Does End-To-End Encryption Mean?

End-to-end encryption is a method of messaging that ensures the privacy of all parties involved, including the messaging service itself. While using E2EE, only the sender and recipient have access to a message’s decrypted version. ‘End-to-end’ refers to the fact that the sender and recipient are both ‘ends’ of the conversation.

In other words, end-to-end encryption can be thought of as a letter that is sent through the postal service in a sealed bag. Both the sender and the recipient of the letter have the ability to open and read the letter. However, the postal workers cannot open the envelope as it is still sealed.

A device’s encryption is necessary for end-to-end encryption. Before they leave your phone or computer, messages and files are encrypted, and then decrypted when they arrive at their final destination. Consequently, hackers are unable to access the server’s data because they lack the private keys necessary to decrypt it. A user’s private keys are instead stored on their device, making it more difficult for a hacker or thief to gain access to their information.

The creation of a public-private key pair is essential for the security provided by end-to-end encryption. In asymmetric cryptography, the use of two separate cryptographic keys protects and decrypts.

  • Public keys can encrypt or lock messages. These are widely available for use by anyone.
  • Private keys are only known to the person who creates them, and they are used to unlock or decrypt the message they are associated with.
The Bob-Alice Example for End-To-End Encryption

The Bob-Alice Example for End-To-End Encryption

The Bob-Alice messaging example is widely used to explain end-to-end encryption. Let us see how they manage to communicate with each other using E2EE.

In our hypothetical example, Alice and Bob have both registered in the system. Every individual participant in the end-to-end encrypted system is given a public-private key pair, with their public keys being stored on the server and their private keys being stored on their device, according to the system’s standards.

Alice wants to communicate with Bob in an encrypted manner. She encrypts her message to Bob using Bob’s public key. He then uses the private key on his device to decrypt the message sent by Alice and reads it.

After reading, Bob simply repeats the process, encrypting his message with Alice’s public key before sending it to her.

Without encryption, another person, say Chuck, can intercept the message for Bob. Alice’s message is safe if she encrypts it with a key that both Bob, and she, have. The message will be decrypted and read if it reaches Bob. He can then decrypt it with the key that he already has in his hands.

Keys can take on different forms depending on the situation.  In the example above, a key could be as simple as instructions for decrypting Alice’s message. A key is a string of bits that one uses in complex mathematical equations to scramble and decode data when communicating over the Internet.

Advantages of End-To-End Encryption

Advantages of End-To-End Encryption

The following are some advantages that come along with end-to-end encryption:

  • End-to-end encryption’s primary benefit is that unauthorized parties cannot read the messages that one is sending. In the same way that a letter is physically impossible to open except by the recipient. End-to-end encryption ensures that your communications remain private.
  • Another benefit of end-to-end encrypted messages is that, other than the recipient, one cannot alter it. Changing the encrypted data causes the message to be garbled when it’s decrypted. One then understands that there has been tampering. One cannot alter Encrypted messages predictably. This means that one cannot replace the text. This ensures the integrity of your communication.
  • One can trust that messages that have been successfully decrypted are the same as the ones that were sent to the recipient and not tampered with in transit.

Limitations of End-To-End Encryption

While there are a lot of advantages to using end-to-encryption, it comes with certain limitations as well:

  • First and foremost, even though the use of end-to-end encryption allows you to mask the content of your message, the evidence that you sent a message to (or received a message from) a specific person is obvious.
  • The server is fully aware of the messages, even though it cannot read the messages that one exchanges on n a particular day and time. Therefore, even communicating with a particular person may bring unwanted attention to yourself in some cases.
  • If one gains access to your device, he can also read and send messages on your behalf. So that no one can impersonate you, you must protect your devices and applications with a PIN code. Due to this, one needs antivirus software to protect devices. Malware on a smartphone has the ability to read your conversation just as if you were in physical possession of your phone. This holds true regardless of the encryption method used to send and receive messages.

It’s also possible that even if you take great care to protect your devices and know for sure that no one has access to your conversation partner’s device, you can’t be certain about the receiver’s device.

Having analysed the pros and cons of end-to-end encryption have provided us with a fair view as to what it really is, how it works and why it is so important. While it might possess certain limitations, end-to-end encryption is currently the most secure method of transferring confidential data, which is why an increasing number of communication services are adopting it as a security measure.

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