If you find that the time has come for you to use an extra level of security to protect your company's online processes, using PKI or Public Key Infrastructure can provide you with exactly what you are looking for. This system is typically issued by a Certificate Authority such as Digi-Sign and consists of two parts, the first is the public key and the second is the user's digital signature. Both parts of the security protocol must match in order for anyone to gain access to the secured information.
PKI Authentication Requires Separate Identifiers in Order to Grant Access
The first part of the PKI authentication is something such as the person's contact information. Typically this is stored in secure location and is referred to as the something you know part of the authentication process. The other half of the protocol is often referred to as the something you have part. This can be an OTP Token, a PKI USB token or a smart card. Without both factors providing a perfect match access is not going to be granted and the protected data is kept secure.