Abstract: Publicly verifiable multisignature makes the leakage of information，which is harmful to information security.Designated verifier multisignatures are privacy-oriented signatures that provide message authenticity only to specific receiver，which is suitable for some specific conditions.The paper proposes two designated verifier multisignature schemes based on ElGamal algorithm and designated verifier signature.One is a verifiably sequential multisignature，the other is a broadcasting multisignature.These multisignature schemes have the attribute of specified receiver，can avoid the leakage of information of both receiver and signatures，and resist forgery and coalition.The size of signature does not increase with signer number.These two schemes ensure the security of receiver and signatures.

Key words: disignated receiver multisignature, sequential multisignature, broadcasting multisignature

摘要： 通过分析指出公开可验证的多重签名会产生信息泄漏，危机信息安全，指出指定验证人多重签名能保护信息的安全性，并设计了两个基于ElGamal体制的方案：一种是可验证的按序多重签名，另一种是可抵制合谋攻击的广播多重签名。两种方案都具有指定验证人的特性，避免了签名者和接收者的信息泄漏，同时签名长度都不随签名者的人数增加而增长，并能抵制伪造和勾结攻击，能保障签名者和签名接收者的安全性。

关键词: 指定验证人多重数字签名, 按序多重签名, 广播多重签名