If a distributed system is built as middleware on anexisting network operating system, then its security may depend onthe security of the underlying local operatingsystems.
    a. true
    b. false

A security policy describes precisely which actions theentities in a system are allowed to take and which ones areprohibited.
    a. true
    b. false

A secure channel necessarily protects senders and receiversagainst interception, modification, fabrication, andinterruption.
    a. true
    b. false

The Data Encryption Standard (DES) is used for asymmetriccryptosystems.
    a. true
    b. false

DES uses 64-bit data blocks.
    a. true
    b. false