by Dan Calloway
Published August 31, 2009 at 3:20pm EST; The Chronicler’s Web
Data that can be read without any special measures is called plaintext or cleartext. The process of hiding or disguising plaintext so that it cannot be read by humans is called encryption. Encrypting plaintext into an illegible format is called ciphertext. Encryption is used to hide information from those for whom the information is not intended, and that includes those who can see the encrypted data. The process of reverting the ciphertext to plaintext so that it can be read by humans is called decryption or deciphering. Thus the steps in the process are taking plaintext and encrypting it into ciphertext, and then decrypting the ciphertext back into plaintext.
public key cryptosystems
Cryptography is the science of using mathematics to encrypt and decipher data. Cryptography allows one to encrypt data that travels across the Internet (an insecure means of transmission) to the intended recipient so that it cannot be read by anyone for whom the data is not intended. Although cryptography is the science of securing data, its companion, cryptanalysis, is the science of analyzing encrypted data and breaking the secure communication. Cryptanalysis involves a combination of analytical reasoning, the application of mathematical tools, finding data patterns, almost infinite patience and determination, and serendipity. The study of both cryptography and cryptanalysis together is known as cryptology.
Cryptography can be either strong or weak depending on two factors: time and resources, needed to reveal the plaintext from the ciphertext. The result of strong cryptography is ciphertext that is extremely difficult to unravel and revert back to the plaintext from which it originated without special tools or a back door, which allows one to bypass the cryptographic security of the encryption. But, just how strong is strong cryptography? Strong cryptographic strength is loosely defined as the measure of cipher strength that even employing all the known computers in the world today making over a billion checks per second would not result in the deciphering of the ciphertext created by the encryption process into plaintext before the end of the known Universe. One would think that strong cryptography would hold up to even the wittiest and smartest cryptanalyst. However, we cannot predict the computing power of tomorrow, and, thus, we must assume that no encryption, regardless of its strength, is impenetrable. What we can say is that the cryptographic strength employed by applications such as PGP (Pretty Good Privacy) is among the strongest known to man. (more…)
Recent Comments