Symmetric Key Cryptography (Non-Technical)

Simply put, Symmetric Key Cryptography is the use of related, often identical, key for both encryption and decryption.

[a/n: I'm back for the time being. How long? We don't really know but let's make the most out of it. So, first on the agenda is the series of non-technical cryptography articles I started almost a year ago. I know this is months past due but then this and that came up then I had this and had to be taken care of that and then that happened... Well better late than never, I guess. Let's just pretend I was able to convince you with my excuses and allow me to deliver what I promised ages ago.]

(In this article I will cover symmetric key cryptography in preparation for a discussion on the Russian One-Time Pads and the German Enigma on the succeeding articles.)

Previous: Earlier Forms of Cryptography (Non-Technical)

Symmetric Key Cryptography

Symmetric Key Cryptography is also known as Secret Key Cryptography where in encryption and decryption is performed using a key that is the related or identical (i. e. symmetric). It relies heavily on the secrecy of the key. The use of this paradigm is often referred termed as Symmetric Key Ciphers, Private Key Ciphers, Secret Key Ciphers, Conventional Ciphers, etc.

 

Earlier Forms of Cryptography (Non-Technical)

(Notes: Continuing the series of articles on cryptography, here I will discuss the two early cryptographic techniques to better prepare readers for succeeding topics where I plan to cover symmetric key cryptography that will run up to the Russian One-Time Pads and the German Enigma which are the highlights of the second world war.)

Spartan SCYTALE. A device used for
early transposition cipher.

Previous: Introduction to Cryptography (Non-Technical)

Earlier Forms of Cryptography

Cryptography is a science and art that is continuously refined by one civilization after another. Some says it dates back to the Egyptians heiroglyphics which are intentionally cryptic to give it importance. Other says that it began with the ancient Chinese whose language have hidden meanings in their words.

 

Introduction to Cryptography (Non-Technical)

(Notes: I’ve been having some interesting debates with a friend lately, and one of the things we did agree upon is the lack of resources in cryptography that the public can easily understand. Well, it is common knowledge that there are discussions in the security community that the best security defense is an educated user. However, there are very few materials on the subject for non-technical users specially on the subject of cryptography. So, I decided to post a series of articles about cryptography (and, maybe, eventually about cryptographic systems and infrastructures) where in I will try to explain it in non-technical terms. For this article, I decided to start with an introduction to cryptography. Here goes…..)

Introduction to Cryptography

Cryptography is such a big word and to understand it better, it would be helpful to know the origin of the word. It came from 2 Greek words Kryptos meaning “hidden” (from kryptein meaning “to hide”) and Graphos meaning “writing”. So, basically, cryptography is secret writing or obscure writing where the message is “hidden” in such a way that only the right person will be able to read it. And for that person to be able to read the right message, he needs to unlock it. And every kind of cryptography is centered around the idea of a “key”.