The word cryptography may not ring a bell with a person who has only rudimentary knowledge of Information Technology. But unknowingly, he/she enjoys the advantages that it provides every day. Cryptography is akin to the Holy Grail, for those who deal in the enterprise of protecting information using Information Technology. Initially, it was only employed by the military to decode enemy messages, but today is being used in things more mundane, such as email. Cryptography deals with all aspects of secure messaging, authentication, electronic money, digital signatures, and other applications.
A major benefit of cryptography is that it serves as a method for employing digital signatures. Digital signatures enable the recipient of information in order to check the authenticity of the information’s origin, and alsoverify that the information is intact. Thus, digital signatures provide authentication and data integrity. A digital signature also provides non-repudiation. This means that it prevents the sender fromclaiming that he or she didn’t actually send the information. These features are every bit as fundamental to cryptography as privacy, if not more.
A digital signature serves the same function as a handwritten signature. However, a handwritten signature is easy to counterfeit. A digital signature is superior to a handwritten signature in that it is almost impossible to counterfeit, plus it attests to the form of the information as well with respect to the identity of the signer. Some people tend to use signatures more than they use encryption. For example, you may not care if anyone knows that you just deposited $1000 in your account, but you do wish to be darn sure it was the bank teller you were dealing with.
Were you aware of those issues?
It protects a message or file from being read by an eavesdropper, who has no other means of access to either the original wording of what is protected, or the key with which it is encrypted. When a message is transmitted to someone, it is converted into undecipherable code, so that no person other than the intended reader would know what is written. Once the message reaches the intended recipient, he’ll require the program that decrypts it.
Julius Caesar was a captain of a primitive form of cryptography. When Caesar sent messages to his trusted acquaintances, he had to guarantee that the messengers wouldn’t read the message. So he replaced every A by a D, every B by a E, and continued through the alphabet. Only person who knew the ‘shift by 3’ rule could decipher his messages. Cryptography can be used in order to encrypt your entire hard disk. It grew extremely complex during World War II, when Germany exploited it to the hilt. They created Enigma machines that would use multiple rounds of alphanumeric random encryption to pass messages from one submarine to the other. For years the allied forces tried to crack the code using countless permutations and combinations; they were only successful when they were able to capture a submarine that had an Enigma machine on board.
Although partially related, stenography shouldn’t be confused with cryptography and it is important to understand that they’re two entirely separate things. While cryptography is the encryption (or obfuscation) of a message to assure that no one except the intended recipient can decipher it, there is still a message right there in plain-sight with cryptography (and in most instances you have that message at your fingertips to work with IF you want to try to successfully break the code).
Cryptography wasn’t always complicated. But the advent of a beast called the Internet destroyed all accepted conventions. The game changed drastically. Cryptography was rendered practically useless since there is no technology that is widely available today, that prevents the Internet Service Provider from seeing what websites the user visits. Routing thorough another server has been used. However, this isn’t a cryptography technique and by no means foolproof.
Cryptography also has a great deal of jargon which scares most first time readers. Demystifying the jargon is half the battle won for elementary cryptologists. The initial message that is sent is called plaintext. This is then encrypted and converted into something called ciphertext. Cryptanalysis is the art of breaking cryptosystems without knowing the decryption key. Cryptology is the survey of both cryptography and cryptanalysis. A cryptosystem is normally a whole collection of algorithms. The algorithms are labeled; the labels are called keys. In order to decode the message, it is essential that the proper key is known. When someone gets access to the message without knowing the key, he is called cryptanalyst. The benchmark of great cryptography is that it appears random when confronted with any kind of statistical testing. But even when statistics fail to unravel the mystery of cryptography, it may be that it could be caught out by an ingenious cryptoanalyst.
There are two types of key-based encryption algorithms: symmetric and asymmetric algorithms. The difference is that symmetric algorithms use the same key for encryption and decryption, whereas asymmetric algorithms use a different key for encryption and decryption. The decryption key cannot be derived from the encryption key. Symmetric algorithms can be classified into stream ciphers and block ciphers. Stream ciphers can encrypt a single bit of plaintext at a time, whereas block ciphers can encrypt a number of bits.
A cryptographic algorithm, or cipher, is a mathematical function employed in the encryption and decryption process. A cryptographic algorithm works in combinationwith a key —a word, number, or phrase—to encrypt the plaintext.The same plaintext encrypts to different ciphertext with different keys. The security of encrypted data is totally dependent on two things: the force of the cryptographic algorithm and the secret of the key.
A digital signature is a small number of data that was created using some secret key. There is a public key that can be used to ensure that the signature was really generated using the corresponding private key. Digital signatures are used to ensure that a message really came from the claimed sender.
When forced to make contact with someone you share the public key, for it implements asymmetric encryption secure key exchange using a public key and a private key. The public key is paid to the world and serves to encrypt data that third parties we will go. These data we receive will then be decrypted by our person using the private key and password we have linked to it. The private key is likewise used to verify that the data we have obtained are legitimate and haven’t been changed by the signature system.
Cryptography is here to stay; it will evolve to fulfill the ever-increasing security needs of computer users all over the world. The next frontier is the Internet. Algorithms have been developed to address the all-permeating influence of Internet Service Providers. However, they’re limited to the realm of hackers. Cryptography will ensure that it’s the norm of tomorrow.