Cryptology vs. Cryptography vs. Cryptanalysis. What's the Difference?

Although the words cryptology, cryptography and cryptanalysis are used interchangeably — strictly speaking — they mean different things. Nowadays, we only use the word cryptography for everything; it's indeed a catch-all for a broad range of intertwined topics. Today’s post not only aims to point out the differences among them but also to show their connections to each other.

To begin with, cryptology is the mathematics, algorithms, and the applications of formulas that underpins cryptography and cryptanalysis. The world of cryptology goes from basic foundations in cryptography (code-making) to modern algebraic cryptanalysis (code-breaking). So, cryptology is clearly divided into two major parts: cryptography and cryptanalysis; with strong connections to each other, which include cryptographic applications, types of cryptography and their algorithms, code-breaking techniques, information theory, number theory and mathematical applications to encrypt data and also break ciphers. 

Curious About Cryptographic Boolean Functions?

In order to have a good understanding of cryptographic Boolean functions, let's get started from scratch, that's, having a look at the very basic concepts. To begin with, all modern computers are composed of very basic logic circuits using very basic gates, called operators which only apply to binary numbers, in other words, 0 and 1. Each type of gate implements a Boolean operation. The finite field ${\mathbb F}_{2}=\{0,1\}$ is also called binary field, and it is of special interest because it is particularly efficient for implementation in hardware or on a binary computer. Using these gates, the rules of Boolean algebra may be applied to design circuits that perform a variety of tasks. For example, integrated circuits. Then, these circuits are all put together to build into more powerful modern computers. 

Exploring What a PhD Is Like

Some weeks ago, it was my pleasure, and honour, to be invited to participate as a panellist in the online event Explore What a PhD is Like organised by PhD Social Support Network from Loughborough University. The event aimed to give undergraduate and postgraduate students a summary of Doctoral Researchers’ lives and an idea of what it’s like to do a PhD at Loughborough University.

With so much confusing and contradictory information out there, it becomes a bit difficult to have a good understanding of many things before embarking on doing a PhD. So I decided to write down my answers for those of you who could not attend the event and are interested in doing a PhD. Because we were four panellists, I just answered some questions, but in this post, I share my answers to all questions, which mainly depend on my personal circumstances and experiences at Loughborough University — And I do hope to help clear some things up. In case that you have any other questions, please let me know in the comment section.

Cryptography is Everywhere

Historically, cryptography was used for secret communication by exclusive sectors only — such as governments, military and spies — since it was crucial and affordable to them. They have long been aware of the consequences of their messages falling into the wrong hands; therefore, this situation has motivated the development of techniques for disguising a message so that only the intended recipient can read it. 

The huge desire for secrecy led nations, kings, and queens to make all-out efforts to ensure the security of communications by inventing the best possible secret codes and ciphers. 

A lover in Victorian times

As the public also became aware of the need to protect personal messages of a highly sensitive nature, they also became comfortable with encipherment. They began to express their cryptographic skills in a variety of ways — for example, young lovers in Victorian England were often forbidden from publicly expressing their affection, and could not even communicate by letter in case their parents intercepted and read the contents. This resulted in lovers sending encrypted messages to each other via the personal columns of newspapers, more specifically, via the classified ads. 

Do You Want to Be a Cryptographer?

Alan Turing

I've always been interested in information security since 2003, but it wasn't until I enrolled on the cryptography module — while studying for a Master in Advanced Computer Science in England in 2018— that I started getting more keen on the mathematical side of cryptography; perhaps it was in part because I cherish mathematics and had the right cryptography teacher. What's more, I admire Alan Turing since he strove to do good work in difficult conditions during World War II; his work saved millions of lives. All of these things together inspired me to immerse myself in the world of cryptography.