sigma.crypto.CryptoConstants.scala Maven / Gradle / Ivy

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Interpreter of a Sigma-State language

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package sigma.crypto

import java.math.BigInteger

/** Constants used in crypto operations implementation. */
object CryptoConstants {
  /** Length of encoded group element in bytes. */
  val EncodedGroupElementLength: Byte = 33

  /** Group used in the signature scheme. */
  val dlogGroup: BcDlogGroup = SecP256K1Group

  /** Secure random generator used in the signature scheme. */
  val secureRandom: sigma.crypto.SecureRandom = dlogGroup.secureRandom

  /** Size of the binary representation of any group element (2 ^ groupSizeBits == ) */
  val groupSizeBits: Int = 256


  /** Group order, i.e. number of elements in the group */
  val groupOrder: BigInteger = dlogGroup.order

  /** A size of challenge in Sigma protocols, in bits.
    * If this anything but 192, threshold won't work, because we have polynomials over GF(2^192) and no others.
    * So DO NOT change the value without implementing polynomials over GF(2^soundnessBits) first
    * and changing code that calls on GF2_192 and GF2_192_Poly classes!!!
    * We get the challenge by reducing hash function output to proper value.
    */
  implicit val soundnessBits: Int = 192.ensuring(_ < groupSizeBits, "2^t < q condition is broken!")

  /** Generates random bytes using secure random generator.
    * @param howMany number of bytes to generate
    * @return generated bytes in a new array
    */
  def secureRandomBytes(howMany: Int): Array[Byte] = {
    val bytes = new Array[Byte](howMany)
    secureRandom.nextBytes(bytes)
    bytes
  }
}