use of public and private keys

2.)Suppose there is a publicly readable file called /etc/public key. An entry in the file for user A consists of a user's identifier IDA, the user's public key, KUa, and the corresponding private key KRa. This private key is encrypted using DES with a key derived from the user's login password Pa. When A logs in the system decrypts Epa[KRa] to obtain KRa. a.)The system then verifies that Pa was correctly supplied. How? b.)How can an opponent attack this system?

STDM

How does STDM yield more efficient use of the bandwidth? How many T-1 lines are needed to make up one OC12 line ? Need to see the calculated out to understand this Explain the differences between TDM and FDM? Hi I have these topics I am trying to understand further please help. thanks

Please show me how a class C IP address: 202.14.5.0

Please show me how a class C IP address: 202.14.5.0. Using 3 bits of subnetting, compute all possible subnets for the given address. Include network and broadcast addresses for each subnet. Show the subnet mask. Please show me the Name of and Describe the 2 different Access Methods for digital cellular. I need a beet understanding on What is IEEE 802.11 and how does it work

Network topologies and a problem. thanks

a. Explain the differences between RIP and OSPF. b. What is the difference between TCP and UDP. c. How many subnets can be created with the following address scheme, 154.234.x.x subnet mask of 255.255.224.0 ?

wireless standards being used

I am looking for as much info on wirless standards here are some questions I have come up with if you have more info on this topic it would be appreciated. thank you