Hello all security/encryption gurus,

Perhaps this is naive, but could someone explain to me how one can hack/decrypt even a relatively simple encoding algorithm? For example - suppose my algorithm is to add 1,2,3 respectively to each character's ascii code of the string I'm encrypting. Therefore the word "secret" becomes "tgfsgw". Now other than just flat out guessing (and the clue that it's a 6 letter word), how could smeone determine that the original word was "Secret" given ONLY "tgfsqw"?

This was a simple algorithm - but taking it a step further and coming up with a more complex algorithm, longer non-repeating key, and using passwords that aren't common words - how the heck could someone "Break" this?

I'm trying to find a reason to justify a "heavy duty encryption software" purchase, but need to justify it via the preceding example first.

Thanks,