In order to provide public key authentication to a user in Public-key Infrastructure (PKI), the authors were widely using the Public-key digital certificate. But this certificate is not validated to authenticate user under security aspects. So, in order to overcome this aspect, they were proposing Specialized Digital Certificate which avails the authentication of user and key agreement for secured transmission of data. It consists of users general information such as digital driver's license, digital birth certificate etc. and trusted security authorities signed digital signature of public information. Also, it doesn't have user's public key. As user, doesn't contain public key and private keys.