Answer:
The time elapsed is 0.017224 s
Solution:
As per the question:
Analog signal to digital bit stream conversion by Host A =64 kbps
Byte packets obtained by Host A = 56 bytes
Rate of transmission = 2 Mbps
Propagation delay = 10 ms = 0.01 s
Now,
Considering the packets' first bit, as its transmission is only after the generation of all the bits in the packet.
Time taken to generate and convert all the bits into digital signal is given by;
t = 
t =
(Since, 1 byte = 8 bits)
t = 7 ms = 0.007 s
Time Required for transmission of the packet, t':


Now, the time elapse between the bit creation and its decoding is given by:
t + t' + propagation delay= 0.007 +
+ 0.01= 0.017224 s
Answer:
c. your friend can hash all possible options and discover your secret.
Explanation:
SHA-256 is a set of hash functions that was designed by the NSA. SHA-2 is considered an upgrade on the set that was its predecessor, SHA-1. A hash is a mathematical function that condenses data in a process of one-way encryption. SHA-256 creates hash algoritms that are considered irreversible and unique. However, one of the properties of hashing algorithms is determinism, which means that any computer in the world would be able to compute a particular hash and get the same answer.