コンストラクタの詳細

• BigIntegerLittleEndianEncoding

  public BigIntegerLittleEndianEncoding​()

メソッドの詳細

• setField

  public void setField​(Field f)

  オーバーライド:

  setField クラス内 Encoding

• encode

  public byte[] encode​(FieldElement x)

  クラスからコピーされた説明: Encoding
  Encode a FieldElement in its (b-1)-bit encoding.

  定義:

  encode クラス内 Encoding

  戻り値:

  the (b-1)-bit encoding of this FieldElement.

• encode

  public byte[] encode​(java.math.BigInteger x)

  Convert x to little endian. Constant time.

  戻り値:

  array of length b/8

  例外:

  java.lang.IllegalStateException - if field not set

• decode

  public FieldElement decode​(byte[] in)

  Decode a FieldElement from its (b-1)-bit encoding. The highest bit is masked out.

  定義:

  decode クラス内 Encoding

  パラメータ:

  in - the (b-1)-bit encoding of a FieldElement.

  戻り値:

  the FieldElement represented by 'val'.

  例外:

  java.lang.IllegalStateException - if field not set

  java.lang.IllegalArgumentException - if encoding is invalid

• toBigInteger

  public java.math.BigInteger toBigInteger​(byte[] in)

  Convert in to big endian

• isNegative

  public boolean isNegative​(FieldElement x)

  From the Ed25519 paper:
  x is negative if the (b-1)-bit encoding of x is lexicographically larger than the (b-1)-bit encoding of -x. If q is an odd prime and the encoding is the little-endian representation of {0, 1,..., q-1} then the negative elements of F_q are {1, 3, 5,..., q-2}.

  定義:

  isNegative クラス内 Encoding

  戻り値:

  true if negative