Chapter

Mobile Phones as Secure Gateways for Message-Based Ubiquitous Communication

DOI: 10.1007/978-3-540-72354-7_15

ABSTRACT For ubiquitous communication self-organising adhoc networks become more and more important. We consider mobile phones as an
appropriate trusted gateway for external machines with low communication needs. A message-based approach is best in such a
scenario with moving mobile phones and machines. We propose a security model for access control to the communication infrastructure
that is also message-based. To meet the requirements of ubiquitous communicating machines, all algorithms on the sender’s
side are based on symmetric cryptography resulting in low computation needs. A sophisticated symmetric key infrastructure
for message authentication provides the necessary key management. The trustworthiness of the mobile phone is achieved by using
the SIM as a secure storage and computing module. This makes it possible to use the mobile phone not only as a user terminal
but also as a trusted infrastructure component of the mobile network.

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