In general, to provide security services at the application layer There are several possible approaches, the first thought is probably the practice be modified for each application separately. Some important TCP / IP applications have done so. In the RFC 1421 Zhi 1424, IETF provides enhanced private message to SMTP-based e-mail system to provide security services. For various reasons, Internet industry is still too slow the pace of adoption of PEM, PEM A major reason is dependent on an existing, fully operational PKI. PEM PKI is a hierarchical organization, composed of the following three levels:
The next year and a half years, Microsoft expects to launch "Windows Mobile." Currently Microsoft only to Samsung, Sony Ericsson and other mobile phone manufacturers to provide mobile phone operating system Windows Mobile. Microsoft hopes to convince PC users, Windows Mobile and Windows computers is the best choice to match. While Microsoft has been a pioneer in the smart phone, but its Windows Mobile software, Apples brand awareness is not as good as iPhone, RIM BlackBerry, Palm and even better product. Microsoft Entertainment and Devices Division President Robbie Bach said: "We are positioning for mobile phones to determine the cycle has done very well. Most people have seen the cool Windows Mobile phones, do not know that it is a Windows Mobile phone. We must clearly express Windows Mobile phone has value. "