Data compression using encrypted text

Abstract only given. Presents an algorithm for text compression that exploits the properties of the words in a dictionary to produce an encryption of given text. The basic idea is to define a unique encryption or signature of each word in the dictionary by replacing certain characters in the words by a special character “*” and retain a few characters so that the word is still retrievable. The question is whether we can develop a better signature of the text before compression so that the compressed signature uses less storage than the original compressed text. This indeed is possible as our experimental results confirm. For any cryptic text the most frequently used character is “*” and the standard compression algorithms can effectively exploit this redundancy in an effective way. Our algorithm produces the best lossless compression rate reported to date in the literature. One basic assumption of our algorithm is that the system has access to a dictionary of words used in all the texts along with a corresponding “cryptic” dictionary. The cost of this dictionary is amortized over the compression savings for all the text files handled by the organization. If two organizations wish to exchange information using our compression algorithm, they must share a common dictionary. We used ten text files from the English text domain to test our algorithm