A brief introduction about Security Issues in Global Communication Networks There are some powerpoints for me to read for preparing a mid-term in a few days later. In order to practice English writing and review the content for the exam at the same time, I choose one of the powerpoint file for making a brief introduction. The brief history of wireless communication is as follows. Marconi, who was called the father of wireless communication, sent out the first wireless information and began the history of it in 1895. Shortly after that, Marconi company was established in 1897. The first wireless message was transmitted from Franch across English channel to England in 1899. Marconi and Braun got Nobel prize in 1909. The first broadcasting station was established in LonDon in 1922. Ericsson company incorporated Marconi company in 2005. The brief history of the modern mobile communication's development is as follows. AMPS was the first mobile communication system brought up in 1971. In 1979, NAMTS in Japan began to run, and the era of 1G was brought up. The Postal and Telecommunication administrations in north Europe applied to European Conference of Postal and Telecommunication administrations for the establishment of Group Special Mobile, GSM in 1982. In 1988, ETSI was established for the normalization of GSM. In 1991, the first mobile phone communication system was bring stepped into the commercial services, which was c called 2G. In 1992, the WARC ensured the standards of IMT2000, which brought about the era of 3G. The comparison between the two kinds of mobile communicaton systems, 1G and 2G, is as follows. The drawbacks of 1G system are numerous. 1G system mainly serves for audio communication and doesn't support digital communication services. The 1G system in different locations or companies are not compatible with each other all over ther world, so the price of mobile phones of 1G and the service fee is always high and hard to drop off. It's easy for everyone to eavsdrop any two people's communication by erecting simple facilities for receiving the messages. Thus, 1G is not very good. 2G is by far better than 1G. In contrast with 1G, the advantages of 2G is clear. The capacity of all cell-phone base stations are much better. Each base station which has a small coverage area is allocated a small part of spectrum. The difference between the allocated spectrum dodges the confliction between base stations. When raveling all over the world, the function of the system remains the same when using the cell phone.2G has the better capacity for keeping the secret of communications. The test and maintainance of 2G system is easier. The current condition of GSM is as follows. Over 1 billion GSM users worldwide. There are 500 GSM networks in 175 countries/areas. It transmits 24+ billion SMS messages per month. It occupies 71% of world's digital communication market. It occupies 68% of world's wireless market. The issues about the security of mobile communication can be classified in three parts: Authentication, Privacy, and Subscriber identity/Location confidentiality. Authentication means mutual authentication. Privacy means data protection, both wireless and wireline. The third part means identity protection, both wireless and wireline. The issues about the security of mobile communication are numerous, such as Active Attacks:Impersonating network elements such as false BTS is possible Key Transmission:Cipher keys and authentication values are transmitted in clear within and between networks Limited Encryption Scope: Encryption terminated too soon at edge of network to BTS. Communications and signaling in the fixed network portion arent protected. Encryption is not used in some networks: . ... The authentication of the identity in GSM is as follows. Mobile phone user transmit their own International Mobile Subscriber Identity(IMSI) to the internet. The internet receives its IMSI and finds the correspondent KI. The internet randomly generates a code of 128 bits and transmits it via the wireless medium to a base station. The base station uses the random code and the KI to compute the correspondent value(SRES). In brief, it is a hash function which is irreversible. The internet makes a comparison with the commputed value and the real SRES to verify the user. The comparison with the safity of GSM and UMTS is as fol --

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