Both Alice and Bob toss a fair coin three times. The probability
that Alice records a different numbers of heads than Bob is given
by A/B, where A and B are relatively prime integers (greatest
common divisor is 1). Find A + B.
Bob flips a coin 3 times.
Let A be the event that Bob flips Heads on the first two
flips.
Let B be the event that Bob flips Tails on the third flip.
Let C be the event that Bob flips Heads an odd number of
times.
Let D be the event that Bob flips Heads at least one time.
Let E be the event that Bob flips Tails at least one time.
(a) Determine whether A and B are...
Alice and Bob play the following game. They toss 5 fair coins.
If all tosses are Heads, Bob wins. If the number of Heads tosses is
zero or one, Alice wins.
Otherwise, they repeat, tossing five coins on each round, until
the game is decided.
(a) Compute the expected number of coin tosses needed to decide
the game.
(b) Compute the probability that Alice wins
2. Bob flips a coin 3 times.
Let A be the event that Bob flips Heads on the first two
flips.
Let B be the event that Bob flips Tails on the third flip.
Let C be the event that Bob flips Heads an odd number of
times.
Let D be the event that Bob flips Heads at least one time.
Let E be the event that Bob flips Tails at least one time.
(a) Determine whether A and B...
Alice solves every puzzle with probability 0.6, and Bob, with
probability 0.5. They are given 7 puzzles and each chooses 5 out of
the 7 puzzles randomly and solves them independently. A puzzle is
considered solved if at least one of them solves it. What is the
probability that all the 7 puzzles happen to be solved by at least
one of them?
By experimenting with throwing 4 coins, find the
following possibilities
1. What is the probability that the image will appear
3 times at most?
2. What is the probability that the image will appear
at least 2 times?
3. What is the probability that the image will appear
1 times at most?
4. What is the probability of the image appearing more
than three times?
5. What is the probability that the image will appear
at least 3 times?
6....
How to generate a key pair for Alice and Bob Respectively
Suppose Alice sends plaintext P= 113, how does she encrypt and
whats the ciphertext C? After Bob receives C, how does he decrypts
it to get the plaintext P? Suppose Alice sends plaintext P= 113,
how does she sign it and what are sent to Bob. How does Bob verify
the signature? Suppose Bob sends plaintext P=113, how does he sign
it and what are sent Alice. How does...
Problem 4 | A modied man-in-the-middle attack on
Diffie-Hellman
Suppose Alice and Bob wish to generate a shared cryptographic key
using the Diffie-Hellman
protocol. As usual, they agree on a large prime p and a primitive
root g of p. Suppose also that
p = mq + 1 where q is prime and m is very small (so p - 1 = mq has
a large prime factor, as
is generally required). Since g and p are public, it is...
Now assume that Alice and Bob are twins, and Alice left Earth
and Bob stayed behind fixing his spaceship. If Alice spent some
time moving near the speed of light before returning to Earth,
which statement is correct when Alice returns to Earth?
a. Alice will say that she is younger than Bob, and he will
agree.
b. Bob will say that he is younger than Alice, and Alice will
say that she is younger than Bob.
c. Alice will...
Suppose 16 coins are tossed. Find the probability of getting the
following result using the binomial probability formula and the
normal curve approximation.
Exactly 6 heads.
Binomial probability =
(Round to 4 decimal places.)
Normal curve approximation almost =
(Round to 4 decimal places.)