Many systems that require a specific person to log in use Voice Print technology. They users voice is first sampled and analysed by the company, then digitized and encrypted onto their system. When that person logs in, he reproduces a certain phrase or set of words. These are then analysed and compared.

Recent advances in this area have made it very difficult to crack. For many years Digital Approximation software was capable of defeating these systems, but this is no longer the case. In most modern systems, the only real way is to obtain a sample of the uses voice directly. Agents can then use Voice Analysis software to reproduce the phrase digitally from that sample.