The Korean Institute of Advanced Technologies (Kaist) has developed a project called “Ltesniffer” that allows users to intercept and analyze traffic in 4G LTE networks. Although the project cannot decrypt encrypted data between a phone and base station, it can provide access to open information such as calling information. The project was recently published on Github and is available for free use.
“Ltesniffer” has the capability to decode specific channels such as PDCCH, PDSCH, and PUSCH, which transmit official information about the component between the base station and mobile phone. It removes data on Download Control Information and Radio Network Temporary Identifier, which contain data transfer parameters.
To use the project, users need specialized communication equipment and a powerful computer. To process traffic from a base station with 150 active users, a computer with at least 16 GB of RAM and an Intel i7 processor is necessary. Intercepting traffic from a phone to a base station requires a USRP X310 type system with two additional transmitters, costing around $11,000.
The Ltesniffer project has a variety of functions, including automatic definition of physical level settings for each phone and support for LTE Security API. It is compatible with LTE Advanced (4G) and LTE Advanced Pro (5G, 256-QAM) and supports duplex channels with frequency separation (FDD) and base stations with a frequency of up to 20 MHz.
With “Ltesniffer,” users can decipher open information about communication sessions and find out who, when, and to whom a call was made. This technology offers a comprehensive analysis of traffic in 4G LTE networks.