Published on August 6th, 2014 📆 | 4602 Views ⚑0
What is Cryptography
What is Cryptography?
Cryptography is a very interesting science of information security. The word Cryptography is derived from Greek kryptos, meaning hidden. Cryptography is not alone word or one word for all related information security science. Words like cryptanalysis, cipher and cryptology are always included in this science. Cryptography includes techniques such as microdots, merging words with images, and other ways to hide information in storage or transit. However, in today’s computer-centric world, cryptography is most often associated with scrambling plaintext (ordinary text, sometimes referred to as clear text) into cipher text (unreadable text obtained after a process called encryption), then back again (known as decryption). Individuals who practice this field are known as cryptographers.
There is also a word, Cryptosystem that you will see a lot in this video course. Procedures and protocols that are used in cryptography makes up a system that is known as cryptosystem. Cryptosystem are mostly referred as computer programs or protocols but I would like it to extend to a much wider plot. It also include human behavior as social engineering is still one of the fastest technique to compromise a system or application. Things like choosing typical password, logging off unused systems, protecting sensitive files also plays a vital role in cryptosystem.
Although, it is considered that 1st use of modern cryptography was by Julius Caesar, who did not trust his messenger when communicating with his governors. But I think the need of encryption came in high demand after the invention of radio as one can tune into your frequency range and intercept your message. But if the transmission is encrypted then things get changed. In recent times, cryptography has turned into a battleground of some of the world’s best mathematicians and computer scientists. The ability to securely store and transfer sensitive information has proved a critical factor in success in war and business.
To understand more about cryptography, let’s call our friends Alice and Bob. Now Alice wants to transfer some information to Bob but wants to do it securely. Alice decided that instead of transferring information in clear text form, I’ll encrypt this text with some algorithm and key. Then I’ll pass this cipher text. Now bob should also have the key and decryption algorithm to read the information.
The two major problems are secure transfer of key and knowledge about algorithm. Things like degree of complexity of algorithm and its randomness also plays a vital role in cryptography. This course is going to be a detailed overview about all these things.