The security of the elgamal Signature If the Discrete logarithm problem can be solved then elgamal signatures can be rge The converse may not be true The exponent k must be private cannot be used twice best. chosen at random 2424 The security of the ElGamal signature • If the Discrete Logarithm problem can be solved then ElGamal signatures can be forged. • The converse may not be true. • The exponent k must be – private – cannot be used twice – best: chosen at random