26-01-2012, 12:57 PM
INTERNET SECURITY
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Introduction: Secure communication is critical, for e-commerce, e-banking, and even e-mail. Additionally, systems are becoming even more distributed. We know that the real world has many people who will try to gain advantage. Mischief in the virtual world is typically remote and criminal faceless. In the real world, we want confidentiality, secrecy and privacy - criminal offences exist to prosecute unauthorised opening of mail. Integrity is also an important aspect, it should be apparent when artefacts have been alteredseals have been used in years gone by to protect documents. Similarly, the authenticity of artefacts needs to be proved. Other things we want in the real world includes non-repudiation (you should not be able to deny doing specific actions, for example if you bought a share you should not later deny it), which is often implemented using the idea of signatures and witnessing.
Data Encryption System: The Data Encryption Standard (DES) has a very controversial history. It was developed on behalf of the US government based on previous work done by IBM.