gistfile1.scala

val chars = "abcdefghijklmnopqrstuvwxyz"
val rand = new scala.util.Random(System.currentTimeMillis) 
def randChar(upperCase:Boolean) = { 
  val ch = chars(rand.nextInt(chars.length - 1))
  if (upperCase) ch.toUpperCase else ch
}
scala> "Ole Christian Rynning".split(" ").map(_.map(ch => randChar(ch.isUpperCase)).mkString).mkString(" ")
res0: String = Aee Ochbivgjm Vgxwuuc