February 28, 2014

Unusual 3G/4G Security: Access to a Backhaul Network

A backhaul network is used to connect base stations (known as NodeB in 3G terminology) to a radio network controller (RNC).

Connection costs for base stations comprise a significant part of provider's total expenses, so it is reasonable to reduce costs related to building and running of such networks, in particular by implementing new technologies.

February 24, 2014

A Sketch of SIP Security

The Internet is a great tool for communication. You can contact other people using e-mail, online chats, voice and video messengers. With the arrival of new cable systems and Balloon-Powered Internet, soon even the penguins of Antarctica will have access to the Internet!

But what about voice? Since there's such wide Internet coverage, why do we need telephone lines?  We could send voice over Internet channels and SIP (Session Initiation Protocol) addresses this need. SIP has a very interesting story but first we want to highlight certain aspects of the protocol.
SIP is the most commonly used protocol for Voice over Internet Protocol (VoIP) services. SIP is a protocol for initiating a session for further data transfer. It transfers information such as login, domain and password in clear text (in open or hash form). Sometimes the authentication process is not supported (connection is established as a combination IP:port).

Next we will examine several threats that can occur while using SIP and methods to exploit them.