One of the characteristics of the modern international systems is the undeniable role the new communication technologies play in different sections of human societies. Modern communication technologies such as satellites and computers have challenged the national authority and sovereignty of Vestfallian states.  Although national states, specially, in the third world countries, extremely resist...

introduction: this research is planning to observe the influence of sense of social security on doctors’ social health in tehran. therefore, it seems that there is a meaningful relationship among doctors’ social health as a dependent variable, and sense of social security of doctors as the main independent variable. also, piety, life satisfaction, social morality and assessing by others as the ...

I f multicast communication appears as the most eficient way to send data to a group of participants, it presents also more vulnerabilities to attacks and requires services such as authentication, integrity and confidentiality to transport data securely. In this papel; we present the protocol Baal’ as a scalable solution to group key inanagement problems and show how Baal resolves the user’s re...

It may seem anomolous that electronic mail and other computer communication systems require cryptographic protection when almost no physical mail is given this protection. The difference is that computer readable traffic is extremely vulnerable to automatic sorting at very low cost. Physical mail would also need to be encrypted if it were all written on postcards and could be sorted at a cost o...