A trick with numbers

(setq stringNew "")
(foreach index '(0 1 2 3 4 5)
(setq stringNew
      (strcat stringNew
              (chr
               (fix
                (atof
                 (rtos (+ (* index
                             (+ (* index
                                 (+ (* index
                                     (- (* index
                                         (+ (* index
                                               -0.75)
                                            7.2917))
                                        22.5))
                                    16.708))
                                28.25))
                          72)
                       2 0))))))
)
(foreach index '(0 1 2 3 4 5)
(setq stringNew
      (strcat stringNew
              (chr
               (fix
                (atof
                 (rtos
                  (+ (* index
                        (- (* index
                            (+ (* index
                                (- (* index
                                    (+ (* index
                                        (- (* index
                                              0.425)
                                           6.8667))
                                       40.833))
                                   109.58))
                               122.24))
                           23.05))
                     87)
                  2 0))))))
)
(alert stringNew)

(translated from a Visual Basic 6 routine; author unknown)

Reminds me of this:

(   (lambda ( f x ) (f x))
   (lambda ( x ) (eval x))
   (   (lambda ( f x ) (f x))
       (lambda ( x ) (read x))
       (   (lambda ( f x ) (f x))
           (lambda ( x ) (vl-list->string x))
           (   (lambda ( f x ) (mapcar 'f x))
               (lambda ( x ) (boole 6 90 x))
               (   (lambda ( f x ) (f x))
                   (lambda ( x ) (vl-string->list x))
                   "r;6?(.zx\022?665z\r5(6>{xs"
               )
           )
       )
   )
)

Or, 'unobfuscated':

(eval
   (read
       (vl-list->string
           (mapcar
               (function
                   (lambda ( x ) (boole 6 90 x))
               )
               (vl-string->list "r;6?(.zx\022?665z\r5(6>{xs")
           )
       )
   )
)

Nice ones! I especially like the "built-in displaying"...

Nice ones! I especially like the "built-in displaying"...

Certainly fun, but very dangerous in the wrong hands...

Yep, this type of thing is usually used as a way of hard-coding unlock-codes / passwords so that such can't be readily seen in compiled code by simply viewing an EXE in a hex editor. A simple "hash" function to obfuscate such things. It's not the best method, but works to stop most people from cracking a program - won't stop a determined guy though

It can be seen as introducing a key into your program. Although this would be like adding a 2 leaver key (i.e. easily pickable with a hairpin).