Many modern enterprises utilize one or more private or protected networks that allow workers to communicate with one another, to access shared information, and to perform every day tasks and functions. In most cases, the private network includes or provides access to sensitive and confidential information. For this and other reasons, the private network is typically restricted to authorized users, such as members of the enterprise.
Traditionally, an authorized user gains access to a protected network by submitting a credential that authenticates the user to the network. The credential is usually a username and password. The username/password credential, however, sometimes offers little security. For instance, because the username is typically some form of the user's name, it can easily be discovered by a malicious user. Moreover, when the password is created by the user, the user typically chooses a phrase that is easily discovered, e.g., the user's birthday, user's child's name. Once the username and password are misappropriated, i.e., stolen, the protected network can be vulnerable to attack.
To address these concerns, biometric features of the user are now being used in lieu of, or in addition to, the username/password credential. Exemplary biometric features include those features that uniquely identify an individual such as a fingerprint and retinal pattern. Other identifying biometric features are voice and speech patterns, which are particularly useful because a voice response can authenticate a user on two levels. For example, if the voice response is an answer to a challenge question, it can be used to authenticate the user based on a voiceprint and based on the response content. Thus, a person impersonating an authorized user would be required to imitate the authorized user's voiceprint and would be required to answer the challenge question correctly.
To implement voice authentication, the requesting user is typically prompted to submit a voice response via a microphone in a computer through which the user is seeking access to the network. The voice response should be of a quality such that an authentication application/module can accurately match the voice response to a stored sample corresponding to the user. This is problematic, however, because the quality and/or performance of a computer's microphone can vary from computer to computer within an enterprise where many different computer models and makes are used. To accommodate this, the matching algorithm can be designed to lower the matching criteria. This approach, however, can compromise security.