REBOL [
    Title: "Greek"
    Date: 3-Jul-2002
    Name: Greek
    Version: 1.0.0
    File: %Greek.r
    Author: "Andrew Martin"
    Purpose: {Greek changes all upper and lower case letters to random letters,
preserving their case, and changes digits to random digits as well.
}
    Email: Al.Bri@xtra.co.nz
    Web: http://valley.150m.com
    Category: [util text crypt 3]
]

Greek: function [
    {Greek changes all upper and lower case letters to random letters,
    preserving their case, and changes digits to random digits as well.}
    Text [string!]  {The text to "greek".}
    ][
    Mark
    ][
    parse/case Text [
        some [
            Mark: Upper (change Mark #"A" - 1 + random 26) |
            Mark: Lower (change Mark #"a" - 1 + random 26) |
            Mark: Digit (change Mark #"0" - 1 + random 10) |
            skip
            ]
        ]
    Text
    ]