Secure Data Transmission over Mobile Voice Channel

Maksim Lind
Nowadays mobile communication is one of the most common forms of exchanging information. Although mobile communication standards were designed with security in mind, a few known vulnerabilities exist. An attacker can penetrate a mobile network and eavesdrop on a victim's conversation or access data servers of the operator where conversation recordings are stored. A number of attempts has been done to address the issue of mobile communication security. Software solutions use a mobile data channel with standard security mechanisms for information exchange. Hardware solutions represent custom phones that create secure voice channel between two such devices. The first solution does not suite users, who do not have access to the mobile data channel. The disadvantage of the second solution is a high cost and an incompatibility with general phones. In this work, we describe an alternative solution, where security is enforced before any information reaches the phone. Sensitive information such as voice is processed in an external device and then passed into the mobile phone as an analog sound signal. The advantage of this approach is that the external unit and can be attached to any phone with a sound input. While building the system, we analyzed a number of existing solutions, tuned parameters and performed experiments. As a result, we came up with a system that performs secure data transfer at a speed of up to 2000 bps and a median error rate of 21 percent. Keywords: Data transmission, voice channel, mobile communication, modulation, encryption.
Graduation Thesis language
Graduation Thesis type
Bachelor - Information Technology
Alexander Tkachenko
Defence year