By Chad Perrin, Special to ZDNet Asia
Tuesday, December 23, 2008 11:14 AM
You can use cryptographic hash functions to provide a little more security when exchanging files. A lot of functionality of software that helps us maintain secure computing environments depends on cryptographic hash functions. The idea behind the design of most cryptographic hash functions is to use a block cipher algorithm that, given an input string, produces a different output string that is unique to that input. For instance, if you input the string "Keep it simple!" and get "a" as your output, this is only really useful if no other input string produces "a" as its output. The output of a cryptographic hash function is of fixed length: no matter how long the input string, whether three characters long or three million, the output string will always be the same length. This output should, as already mentioned, be unique to the input so that changing a single character produces a different output string (known as a "hash" or "checksum"). Furthermore, predicting the output hash of a given string should be effectively impossible. These cryptographic hash functions serve myriad purposes. Read more » |
