encryption/decryption functions that take a key (as an integer in 0, 1,2, ... , 25), and a string for plaintext. I try it.. but my key is a constant.. it doesn't change! I use java code.. any ideas?

Question

e.mccormick · Answer

Well, are you doing the Ceaser Cypher or something like that?

anonymous · Answer

Yes! Is the ceaser cipher!

e.mccormick · Answer

OK, do you know how to represent a character as a number?  Thinking about that will help.  Also, do you know how the % operator works?  Because it can be very useful for when a number wraps...  like if I have something that travles right and goes off the right side of the screen, the % operator can change it so it comes back to the left side.  Well, something similar can be done if you want to shoft letters.  Say I had an arrray of a to z, with a at postion 0 and z at position 25.  Now, lets say I shoft by adding 15 to the value.  Well, w + 15 is 22 + 15 = 37!  There is no element 37 in the array!  But, (22 + 15) % 26 = 11 or k.  That should give you some ideas to work with.