「数字6桁パスワードのMD5ハッシュ値の総当たり」Scalaは1.70秒だった ref: http://qiita.com/nmatsui/items/dd70fd57d81bdd935f79

FindPassword_Single.scala

import java.security.{MessageDigest => MD}

object MD5FindPassword_Single_WithFormatter {
  def findPassword(salt:String, pw:String):Option[Int]  = {
    def hexdigest(s:String):String = {
      val digester = MD.getInstance("MD5")
      digester.update(s.getBytes)
      digester.digest.toList.map(_&0xff).map("%02x".format(_)).mkString
    }
    (0 to 1000000)
      .find(i => hexdigest("%s$%06d".format(salt, i)) == pw)

  }
  def main(args: Array[String]) {
    findPassword(args(0), args(1)) match {
      case Some(f) => printf("match [%06d]%n", f)
      case None    => printf("not match%n")
    }
  }
}

MD5FindPassword_Parallel_NoFormatter.scala

import java.security.{MessageDigest => MD}

object MD5FindPassword_Parallel_NoFormatter {
  def findPassword(salt:String, pw:String):Option[Int]  = {
    def hexformatter(x:Int):String = {
      val h = Integer.toHexString(x)
      "0"*(2 - h.length) + h.toString
    }
    def mkOrigin(x:Int):String = {
      val xs = x.toString
      salt + "$" + "0"*(6 - xs.length) + xs
    }
    def hexdigest(s:String):String = {
      val digester = MD.getInstance("MD5")
      digester.update(s.getBytes)
      digester.digest.toList.map(_&0xff).map(hexformatter(_)).mkString
    }
    (0 to 1000000)
      .par // 変更点はココだけ
      .find(i => hexdigest(mkOrigin(i)) == pw)

  }
  def main(args: Array[String]) {
    findPassword(args(0), args(1)) match {
      case Some(f) => printf("match [%06d]%n", f)
      case None    => printf("not match%n")
    }
  }
}

MD5FindPassword_Parallel_WithFormatter.scala

import java.security.{MessageDigest => MD}

object MD5FindPassword_Parallel_WithFormatter {
  def findPassword(salt:String, pw:String):Option[Int]  = {
    def hexdigest(s:String):String = {
      val digester = MD.getInstance("MD5")
      digester.update(s.getBytes)
      digester.digest.toList.map(_&0xff).map("%02x".format(_)).mkString
    }
    (0 to 1000000)
      .par // 変更点はココだけ
      .find(i => hexdigest("%s$%06d".format(salt, i)) == pw)

  }
  def main(args: Array[String]) {
    findPassword(args(0), args(1)) match {
      case Some(f) => printf("match [%06d]%n", f)
      case None    => printf("not match%n")
    }
  }
}

MD5FindPassword_Single_NoFormatter.scala

import java.security.{MessageDigest => MD}

object MD5FindPassword_Single_NoFormatter {
  def findPassword(salt:String, pw:String):Option[Int]  = {
    def hexformatter(x:Int):String = {
      val h = Integer.toHexString(x)
      "0"*(2 - h.length) + h.toString
    }
    def mkOrigin(x:Int):String = {
      val xs = x.toString
      salt + "$" + "0"*(6 - xs.length) + xs
    }
    def hexdigest(s:String):String = {
      val digester = MD.getInstance("MD5")
      digester.update(s.getBytes)
      digester.digest.toList.map(_&0xff).map(hexformatter(_)).mkString
    }
    (0 to 1000000)
      .find(i => hexdigest(mkOrigin(i)) == pw)

  }
  def main(args: Array[String]) {
    findPassword(args(0), args(1)) match {
      case Some(f) => printf("match [%06d]%n", f)
      case None    => printf("not match%n")
    }
  }
}