Encrypting and decrypting the Text Content

Question

Hi All Presently i am working on C#.net. In my application i am giving input of text content of any length. but i want encrypting text should be of 20 length. This encrypting text should be get back to my original text when i decrypt it. Note: Special charactes like + / = should not come in the encrypted text. I will be thankful if any one can help me out in this regard. Thanks in Advance Vasu.

alobiuc · Answer

You're not quite clear in what you're saying. You say that given a text of any length a certain algorithm should produce an output with a length of 20 (btw 20 what? bytes characters)? I assume you meant characters. If so then this would be mainly an compression algorithm. And if so good luck with it! If you can compress any text to 20 characters then you're the toughest 'n roughest programmer the world had seen. Anyway I personally don't think that's possible. However for compression algorithms use Google. I think I saw somewhere the source code for the LZW algorithm (one of the oldest algorithms). [QUOTE]:This encrypting text should be get back to my original text when i decrypt it.[/QUOTE] That's the main purpose of an encryption algorithm. After all what can you do with an encrypted text if you can't decrypt it? I also recommend google search for this one too. I myself am interested in encryption and I've came across some interesting sites (I didn't bookmark them  unfortunately). Yet what kind of encryption are you looking for? A domestic one? If so you can use old and simple algorithms like ROT15 (which basically ROTates the position of a given letter with 15 letters to its right). If you want more powerful encryption use the .Net Encryption namespace methods that implement RSA and DES algorithms (some of the most used algorithms around). And finally if you want bleeding-edge algorithms get yourself some radioactive substances and use one time pad encryption ;) As another option if you have some skills in mathematics write your own algorithm. You can start like I did encrypting a plaintext with a key by simply adding in rounds the key to the plaintext. It might look like it rocks if you look at the resulting ciphertext but it's a false impression.