Friday 12 March 2021

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. 

But what exactly is cryptography? Simply put, it is the study of how to send secret messages by codes and ciphers, in other words, cryptography is the art and science of keeping messages secure. Perhaps the most famous encryption machine is the Enigma which was developed by Nazi Germany to protect commercial and military communication during World War II and then cracked by Alan Turing — it is difficult to avoid getting excited when talking about the Enigma machine, isn't it? During that time, he worked for the Government Code and Cypher School (GC&CS) at Bletchley Park, Britain's codebreaking centre. He played a decisive role in cracking intercepted coded messages which enabled the Allies to defeat the Nazis and shorten the war by as many as two to four years. This certainly saved millions of lives as well. 
The Enigma Machine

With the arrival of major advancements in science and technology, this field has played an extremely important role beyond military’s security becoming financially and technologically accessible and increasingly essential for ordinary people and companies. 
Nowadays, cryptography is not only about secret communication but also data security — including confidentiality, integrity, authentication and non-repudiation. 
It is commonly used for e-commerce especially electronic transactions in the banking system, cash withdrawal from an ATM, instant messaging, file storage, email, web browsing, GSM mobile phone, cryptocurrency, etc. We are using cryptography more than ever before.

Notwithstanding the beneficial impact on society, cryptography has also raised some concerns related to human rights, ethical, and legal issues because it can certainly be used for bad purposes as well — such as organising terrorist attacks and abusing people. In this sense, companies have a duty to protect data based on contract, laws, and industry regulations related to Copyright and Digital Rights Management. Also, some governments have the right to request key disclosure either from the accused or from third parties, but it also compromises people's privacy.
Having the forces of law and order lobbying to restrict the use of cryptography gives rise to the heated controversy over which one has more value for us: our privacy or an effective police force? This controversial issue certainly conflicts with both sides' interests. 
Not surprisingly, issues like this are being addressed by the global movement Amnesty International which says Encryption is a matter of Human Rights, which basically means that people everywhere should be able to encrypt their communications and private personal data for the sake of their rights to privacy and free speech.

Code-breaking attacks have also been improved considerably resulting in cryptographers working on new ways to make stronger cryptography which thrives only until its weakness is identified by codebreakers. So, secret codes and ciphers are constantly under attack from codebreakers which continually force them to evolve to survive the onslaught of new attacks. This ongoing battle has resulted in remarkable scientific breakthroughs and accelerating technological developments. Also, this situation has mostly looked like a quest for absolute secrecy — which is not possible for now at a reasonable cost. 
Cryptography is everywhere, and you might have not noticed yet; it is because cryptography is mostly working in silence — in the background — it is invisible; it is always working in the dark to help secure our communication and data. It is always there to protect us.
I must mention that cryptography is a central topic within theoretical computer science, which covers a broad range of key-related topics having maths as the game-changer. It is strongly linked to mathematics, algorithms, etc. Good cryptography needs good mathematics, and it is practised by cryptographers who are trained in theoretical mathematics.

Cryptography is just wonderful — Welcome to the freewheeling world of cryptography... 


  1. That is very interesting Percy. I'd like to see more posts about this and maybe how the prime factorization is applied to solve those problems in Cryptography. Well done.

    1. Hi Nelson, thanks for your comment.
      As of prime factorization, it is used in public-key cryptography (asymmetric cryptography), for which it is the core. I will write some posts about that in the foreseeable future.

  2. That is really interesting. Reading this reminds me of the movie "The Imitation Game", where cryptography is shown as the key topic to decipher Enigma.

    1. Yes, it is actually intriguing and inspiring!

  3. The debate around security vs privacy is interesting here, especially considering moves by some governments to get outright access to all forms of encrypted communications. Would love to know your thoughts on this !

    1. Hi Adam. Thanks for your comment.
      Well, it's a quite controversial topic. People trying to keep their privacy while Governments trying to do their job to protect us from terrorists and other attacks, which means less privacy for us. The problem's root is that many people, including those from Governments, mostly care about their ulterior motives. Unfortunately, it turned out to be more of a political/business issue. The Governments’ abuse of power lead people not to trust them, the same happens with companies using our data to make big money, have you heard about Big Data? So you got the idea. On the other side, we have terrorists making the most out of this situation.
      People see not only the terrorists as enemies but also companies and Governments, so people don't trust each other, we are always looking for new highly effective techniques to protect our privacy. It has always been a never-ending story...
      I'm convinced the problem is people, not cryptography itself.
      People don't understand technology neither computer nor cryptography. People don't understand risks. People don't understand subtle things threats. People always are the weakest link in the security chain.
      "cryptography is a miracle, mathematics is impeccable, the computers are vincible, the networks are lousy, and the people are abysmal - Bruce Schneier"

  4. Very well explained its need and future implications!!


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HELLO, I'M PERCY REYES! — a book lover, healthy lifestyle lover... I've been working as a senior SQL Server Database Administrator (DBA) for over 20 years; I'm a three-time awarded Microsoft Data Platform MVP. I'm currently doing a PhD in Computer Science (cryptography) at Loughborough University, England — working on cryptographic Boolean functions, algorithmic cryptanalysis, number theory, and other algebraic aspects of cryptography. READ MORE