Prevention of SPIT using the Concept of Access Number (AN)

摘要

This paper considers the importance of VoIP in today’s communication, its security issues and in particular the issue of SPIT. In order to prevent SPIT a mechanism has been proposed which uses the concept of an Access Number (AN) which is similar in function to the PIN number of a debit card. This mechanism uses a combination of some existing potential SPIT prevention solutions with a new idea of changeable AN number. The mechanism prevents the spitter from accessing the AN number but makes it available to the legitimate caller. The AN number can be achieved at the price of time, information about the callee and/or cost. (These factors will be negligible/zero for the legitimate caller but significantly high/impossible for the spitter). A changeable characteristic of the 4 digits AN number is the key feature of this mechanism. If in any case the spitter gets the AN number of a certain user, the user can simply change his AN number and the spitter needs to strive again for accessing the AN number but the legitimate caller will not require the new AN number.