Cryptography is a field of science involved with the encryption and decryption of data such that when a data is encrypted with a password, it is rendered unreadable or completely unusable until it is decrypted by either the same password or another of a suitable nature. It would be preferable that the password for decryption be held only by the intended viewers such that the encrypted data becomes completely secure and is only accessible to those who are supposed to access it. Without the correct password for decryption, a hijacker is unable to use the encrypted data in any way whatsoever unless he manages to crack the algorithm used to encrypt the data. Strong algorithms will require hundreds or thousands of years with current hardware to crack while the weakest ones take average hardware slightly over a few seconds to break.
Julius Caesar (who was believed to pioneer cryptography) invented a code language called the Caesar cipher.
In the olden days, messages had to be conveyed during wars to instruct troops to carry out certain battle plans. As there were no modern communication devices then like the satellite and telephone, generals had to depend on messengers on horseback to deliver the messages. The danger was that the rider could easily be intercepted on his way to deliver the message, making it possible for the enemy to know where the opposing troops were located and how to ambush them. This would make it easy for them to be able to defeat their opposing army easily.
To counter such a consequence, Julius Caesar (who was believed to pioneer cryptography) invented a code language called the Caesar cipher. It was an easily broken code, but in a time where cryptography was unheard of, it became a major factor in him winning his wars. The Caesar cipher worked simply by shifting the letters in the alphabet by an arbitrary number of positions by the setter of the code. The receiver, having already known the number of positions the letters were shifted, would just as easily shift the letters back and retrieve the original message. For example, “The river flows” became “uif sjwfs gmpxt” if all the letters were shifted by one.
As the decades and centuries passed, more and more insecure communication channels came to be and there was a need to invent much more powerful forms of cryptography. This was also partly due to the invention of faster and more powerful hardware which are able to crack the weakest algorithms in the blink of an eye. Now, there are already expert code breakers who work solely as cryptographic experts and devote their time to finding ways of breaking and cracking cryptographic algorithms.
Symmetric cryptography
Symmetric cryptography is the kind of cryptography where one password is used to both encrypt and decrypt a message or any other forms of data. Some examples of symmetric cryptographic systems include the Caesar cipher and XOR cipher. Both involve only simple mathematical relations to encrypt and decrypt data. Generally, symmetric cryptosystems are less secure as they usually involve weaker algorithms and they also pose the problem of the transmission of the password. How do you transmit the password to those who intend to encrypt a message only for your viewing? If you can transmit it through a secure enough channel, then why use encryption in the first place? To the inexperienced cryptanalyst, symmetric cryptography may pose a problem to crack but to most experienced cryptanalysts, these algorithms will not take them more than a few hours to crack.
Asymmetric cryptography
Asymmetric cryptography is of course the opposite of symmetric cryptography. It involves a public key, which is used to encrypt the message, and a separate private key, which is used to decrypt the message. Asymmetric cryptography is also more commonly called public key cryptography. Some examples include RSA and DES. Asymmetric cryptography is generally much stronger and is more convenient as separate keys are used to encrypt and decrypt the message. As such, the public key can be freely distributed to anybody for encryption of data only for the holders of that public key’s corresponding private key. Asymmetric cryptography use one way mathematical functions in such a way that it takes a nearly infinite amount of time to find the private key that will decrypt the message that the public key message encrypts. As such, asymmetric cryptography is very highly secure and is the most common type of cryptography used today.
Today, many cryptography software exist, which give decent amount of protection for your data.
This being an information age, the amount of data that we deal with everyday is a frighteningly huge amount. Some of the data that we transmit over communication channels are meant only for the receiver to read and view but as these channels are open to the public, there is no stopping it from being accessed by anybody who wants to see it for whatever ulterior motive they may have.
Therefore, it is imperative that you encrypt your sensitive information using cryptography. Today, many cryptography software exist, which give decent amount of protection for your data. Try searching for software that implements cryptography using a search engine, such as Google.
Alternatively, you can also check out our encryption engine. It does not use a very strong cryptography algorithm, but it serves as a demonstration and an insight into the world of cryptography.
Cryptography is emerging as a very important tool in the field of security today. With security becoming a very important field in the world of today, cryptography is being catapulted into the limelight together with other methods of security. Indeed cryptography is one of the first lines of defense against hackers and crackers in today’s world. Thus, it will stay important for a long time to come as it has for thousands of years since Caesar first invented the Caesar cipher in an era before the birth of Christ.
Related link: Learn about Steganography, which offers you another way of protecting your information
Reference
A Short History of Cryptography
http://www.all.net/books/ip/Chap2-1.html
Handbook of Applied Cryptography by Alfred J. Menezes, Paul C. van Oorschot and Scott A. Vanstone