Towards Security of GSM Voice Communication

Global system for mobile communication (GSM) is widely used digital mobile service around the world. Although GSM was designed as a secure wireless system, it is now vulnerable to different targeted attacks. There is a need to address security domains especially the confidentiality of communication. This paper presents a novel framework for end to end secure voice communication over the GSM networks using encryption algorithm AES-256. A special Modem and speech coding technique are designed to enable the transmission of encrypted speech using GSM voice channel. To the best of our knowledge, this is first solution that uses single codebook for transmission of secure voice. An efficient low bit-rate (1.9 kbps) speech coder is also designed for use with the proposed modulation scheme for optimal results. Different speech characteristics such as pitch, energy and line spectral frequencies are extracted and preserved before compression and encryption of speech. Previously, the best achieved data rate was 1.6 kbps with three codebooks, whilst the proposed approach achieves 2 kbps with 0% bit error rate. The empirical results show that the methodology can be used for real time applications to transmit encrypted voice using GSM network

The mobile commerce technologies: Generations, standards and protocols

Mobile Commerce has staged a remarkable come-back. Driven by the technological innovations in the field of telecommunications, it is showing signs of a healthy recovery. The collapse of the dot-com boom in 2001/2002 had dealt a severe blow not only to Electronic Commerce but also to Mobile Commerce, which was just about developing at that time. In addition to a general lack of customer demand for mobile, location-based, services, it suffered heavily under the technical deficiencies of end-devices, slow data transmission and unripe technological standards. These factors in turn had a negative impact on the customer acceptance of mobile services and whatever little demand was available, was rendered useless. Many of the environmental conditions have changed since then. Technology innovations have reduced many barriers to acceptance. Increasing globalization has led to more mobility and therefore to greater demand for mobile, ubiquitios services that can be consumed anytime, anywher. This paper examines different telecommunication technologies regarding their suitablilty and deficiencies. It provides an overview over the historical development of mobile technologies while pointing towards the expected future scenario. --Mobile Commerce,M-Commerce,UMTS,WLAN,3G

Solutions to the GSM Security Weaknesses

Recently, the mobile industry has experienced an extreme increment in number of its users. The GSM network with the greatest worldwide number of users succumbs to several security vulnerabilities. Although some of its security problems are addressed in its upper generations, there are still many operators using 2G systems. This paper briefly presents the most important security flaws of the GSM network and its transport channels. It also provides some practical solutions to improve the security of currently available 2G systems.Comment: 6 Pages, 2 Figure

Secure Data Transmission over Mobile Voice Channel

Tänapäeval on mobiilside üks levinumaid viise informatsioonivahetuseks peale silmitsi suhtlemise ja interneti. Kuigi mobiilside standardid tagavad kõnede turvalisust, on neis ka teadaolevaid turvaauke. Kindlates olukordades võib kurjategija mobiilikõnet pealt kuulata või pääseda juurde mobiilioperaatori poolt salvestatud kõnedele. Mõned turvalise mobiilikõne lahendused kasutavad andmeedastuseks internetti. Teised pakkuvad spetsiaalseid telefone, mis loovad omavahel turvalist häälekanalit. Esimene variant ei sobi inimestele, kellel pole ligipääsu mobiilsele internetile, teine variant on aga kallis ning seda ei saa kasutada teiste telefonidega. Selles töös me kirjeldame lahendust, mis tagab turvalisuse enne kui informatsioon jõuab telefonisse. Tundlikud andmed töödeldakse eraldiseisvas seadmes ning saadetakse telefonisse analoogse helisignaalina. Sellist seadet saab ühendada igal telefoniga, millel on ette nähtud heli sisend. Töö käigus me vaatlesime erinevaid olemasolevaid lahendusi, seadistasime süsteemi parameetreid ja viisime läbi katsed. Tulemusena me saavutasime süsteemi, mis edastab turvaliselt andmed kiirusega kuni 2000 biti sekundis ja veamäära mediaaniga 21 protsenti. Võtmesõnad: Andmeedastus, häälekanal, mobiilside, modulatsioon, krüpteerimine.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