What is Cryptography and is it here to stay? Cryptography is the act of encoding messages in such a way that only intended recipients can read them. These messages are called encrypted messages and provide an additional safeguard against unwanted third parties. In this blog post, I will be giving you a short introduction to cryptography and why it is important for us all to learn about it. Hopefully, after reading this blog post you will have a stronger understanding of what cryptography really is and how it’s used today.

What is Cryptography?

Cryptography allows users to send secret messages that can’t be intercepted by other people without access to the encryption key used while sending the message. It has many uses today, especially when we look at how it is implemented in different technologies. Some of these technologies are listed here.

One very common use of cryptography is encrypting Passwords on your mobile device to ensure that no one can see them.

To encrypt data stored on your device and keep only you have the authorization to see it. For example, WhatsApp messages can be encrypted on your own phone, thus making them unreadable for anyone who does not have the encryption key. This means that even if your phone is stolen, other people won’t be able to access those messages without the encryption key which is only accessible by yourself.

To send secure messages via email or chat applications like Whatsapp or Facebook messenger.

Let’s start with encryption on mobile devices. This can be used in many different ways, the main purpose is to ensure that messages sent by you are safe against other people reading them. The end goal is to keep your messages and details private from prying eyes.

The hardware devices available today when buying a mobile phone come with software installed into them, that allows these phones to communicate with applications like Whatsapp, Facebook messenger or even your Gmail account. Now, this all depends on how secure you want those applications to be and what level of encryption you want to be applied for those messages to be secure. There are two main forms of encryption on mobile devices today, symmetric and asymmetric encryption.

a) Symmetric encryption

Symmetric encryption is where the same key is used to encrypt and decrypt the data. This means that only a single entity can decrypt the message. In which case, if a hacker wants to read these messages, they will need access to that encryption key.  This makes this method of encryption very secure. This is implemented in WhatsApp and Facebook messenger.

b) Asymmetric Encryption

Asymmetric encryption can also be referred to as public-key cryptography because it uses two keys, one key for encrypting messages (public) and another for decrypting them (private).
This is usually used with public-key cryptography which allows the owner of a private key to encrypt data. For example if you have a very important message to send, maybe a text message or an email, you will use your own private key to encrypt that message and send it out. Only the receiver of that message will be able to decrypt it with their own private key, which can only be accessed by them.

So now we can see how encryption can be used for almost any kind of data protection scenario. If a hacker were to steal your phone, they would not be able to read your messages unless they had the private key which only you could access.

So that brings me to the next topic; how is cryptography used in public-key cryptography?

In public-key cryptography, two keys are used; one is the public key, and the other is the private key. The messages sent using these keys are generally secure because only one of the two recipients of these messages will be able to decrypt them. They are called asymmetric because their function is different from traditional encryption systems which use a single key for both encryption and decryption. The main feature of this system is that anyone can encrypt a message but only the receiver can decrypt it.

Is cryptography here to stay? 🤔

Through the history of cryptography, there have been many changes. The first major change was when people started using codes to indicate messages. For example, you might see Batman or James Bond on the front of a postcard and this would indicate that they are delivering a secret message to someone. These days we use symbols, colours and other ways of communicating information via telegraphs, radios and telephones but the original concept has stayed the same.

The next major change in cryptography came in World War 1 when encryption systems became more commonly used to send encrypted messages between military officers in different countries during wartime.

Cryptography has advanced since then, with the introduction of digital encryption systems. These types of encryption were first used by governments and militaries to ensure that sensitive information was not decrypted by others. They are public-key applications because they use two keys for encryption and decryption, in which only one key can decrypt the information. This key has a value (numbers) known only to the operator who sent it and can be used as a password to access their encrypted computer file.

Advantages of Cryptography 👍

1) To maintain privacy and stop third parties from viewing content we don’t want them to see.

2) To prevent hackers from stealing sensitive information from your business. For example, a hacker might want to steal your client’s credit card information while they enter it into your online shopping site or business website (i.e eBay).

3) To stop anyone from intercepting information you are sending to a government agency, tax authority or other places where privacy is of concern.

Disadvantages of Cryptography 👎

The only disadvantage that we see with cryptography is the fact that it may be used in the wrong way by governments to spy on citizens and that it could potentially reduce people’s privacy. In countries like China, Russia and the United States, there is no guarantee that governments will not use encryption for spying purposes. This can also be true for large organizations like Google and Facebook which can sell personal data to third parties which can then unknowingly sell this data to other companies who may use this information for their own benefit.

Conclusion

As we have seen, cryptography is a process of securing data by using algorithms to encrypt messages so that only the intended receiver can decrypt them. I hope that this article has been helpful in explaining the basics of Cryptography from a Computer Science point of view.

You might be interested on the advantages and disadvantages of code obfuscation.