What is Encryption?
What is encryption? Broadly, it is the act of taking information and transforming it into something that can only be read using a key. The entity that transforms the information is called the algorithm.
Today, encryption is thought of as a means of computer security. However, the roots of encryption go much deeper than computers and extend to a whole host of information that people want to keep secret. Prior to the Internet, encryption was a tool used primarily by the military rather than the public. It is still widely used by military agencies, but today the public also has an interest in encrypting their personal data on their computers.
In the past, encryption was still as important a tool for protecting information as it is today. Encryption has been used in various forms for thousands of years. Classical cryptography is found in Egypt dating back to around 1900 B.C. There, non-standard hieroglyphs were used to create mysteries and puzzles.
Later on, the practice became less playful. Circa 500 or 600 B.C., the Hebrews were using simple substitution ciphers to code messages. This simple encryption method took one letter and replaced it with another to scramble the message.
In medieval times, the definition of what is encryption changed again. Cryptology used both substitution and transposition techniques to encrypt messages. In addition, advanced methods of breaking encryption started to develop. Arab mathematicians began to come up with ways to break the codes and extract information from encrypted data.
At the same time, the Renaissance in Europe was leading to more advanced methods of encrypting data. Encryption was used extensively by politicians and the church, who had a lot of information that they wanted to protect and keep secret. They began a trend that resulted in a rapid proliferation of different encryption techniques.
War can also motivate innovation in encryption - that was certainly the case with World Wars I and II. During World War II, Poland and some other nations even had Encryption Bureaus. The countries involved in the war spent a tremendous amount of time, energy and resources on both creating encryption systems and breaking those systems.
Nowadays, most encryption happens electronically. Computers are encrypted to protect users’ data. This is important not only to governments and military agencies, but also to ordinary citizens. With banks, taxes and other personal data being stored and updated right from home computers, it is now in the interest of most people to have some form of encryption.
The “key” has become an important element of encryption. There are symmetric and asymmetric key algorithms in use now. Symmetric key algorithms means that both the sender of information and receiver of information have the key. There must be trust on both sides for this system to work, as both people hold the key to break the encryption. In asymmetric key algorithms, less trust is necessary. Each person has a key, but all it does is decrypt the encryption imposed by the other person. The keys are mathematically related, meaning that they can decrypt the encryption caused by the other key.