A security breakthrough for mobile phones, which safeguards access to handsets by means of voice authentication, was announced by SchlumbergerSema, a business unit of Schlumberger Limited who joined forces with Domain Dynamics Limited, the UK voice and signal specialist.

Unlike previous attempts at introducing biometric technology for this application, the new system runs on a SIM (subscriber identity module) card and requires no additional hardware, making it cost effective, simple to introduce.

The technology ensures that only legitimate users can access a phone - or its resources such as phonebooks - by means of a locking mechanism which operates in the familiar fashion of a PIN code. The authentication routine simply requires the user to speak a set phrase or word as the phone is switched on, which is compared in real-time with a reference voiceprint stored inside the tamper-proof SIM card’s memory.

This unique voice authentication system provides an ideal solution both for the current problem of mobile handset and service theft, and a safeguard for industry progress - as higher bandwidths start to allow mobile phones to be employed for m-commerce and confidential transactions.

“Voice authentication is the most natural method of introducing state of the art security into the mobile phone marketplace”, says Jorgen Rasmussen, president Cards at SchlumbergerSema. “By basing the solution on the standardized SIM platform, it becomes cost effective and simple, providing a highly flexible mechanism for operators to address the widespread public concern over this issue”.

The new system has been developed by a partnership between SchlumbergerSema who provides the SIM ToolKit applet, Domain Dynamics Ltd who provides the voice authentication algorithm, and Mitsubishi who have implemented the technology on the Trium Mondo GSM/GPRS phone.

The system is provided as a SIM ToolKit applet which may be loaded onto any standard Javacard SIM. Thanks to the unique nature of the signal processing algorithm designed by Domain Dynamics Ltd, and the lean nature of the man-machine interface program, the applet is extremely small - requiring just 2.5 kbytes of memory in total.

This tiny memory usage includes everything required for the deployment and use of voice authentication: from the enrolment process which lets a user enter his or her voiceprint (by repeating a chosen word or phrase three times), through the generation of the reference biometric template which stores the key characteristics of the voice, to the sign-on and comparison procedure for daily use.

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