public final void initSign(PrivateKey privateKey) throws InvalidKeyException 用指定的私鑰初始化 參數:privateKey 所進行簽名時用的私鑰
public final void update(byte data) throws SignatureException public final void update(byte[] data) throws SignatureException public final void update(byte[] data, int off, int len) throws SignatureException 添加要簽名的信息
public final byte[] sign() throws SignatureException 返回簽名的數組,前提是initSign和update
public final void initVerify(PublicKey publicKey) throws InvalidKeyException 用指定的公鑰初始化 參數:publicKey 驗證時用的公鑰
public final boolean verify(byte[] signature) throws SignatureException 驗證簽名是否有效,前提是已經initVerify初始化 參數: signature 簽名數組
