Week two!
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8 groups of 2
5 rounds
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Math 1
Modern history
Math 2
Computer Programming
Analyzing and comparing Cryptosystems
10 questions per round
Each question is worth 1 point
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Find a field with 7 elements.
Find a field with 9 elements.
Multiply 𝑥 + 1 𝑥 + 3 in 𝔽25 = ℤ5 𝑥 mod 𝑥 2 − 2.
Find 𝑥 10 + 𝑥 3 in 𝔽256 = ℤ2 𝑥 mod 𝑥 8 − 𝑥 4 − 𝑥 3 − 𝑥 − 1
Find all quadratics in 𝔽256 .
Find 𝜑 77
Convert 00011101 2 to 𝔽256 .
Convert 00011101 2 to hex.
Convert 0x5𝑎 to decimal.
How many bits would it take to represent a 100digit number?
1.
2.
3.
4.
5.
Name a fundamental paradigm shift in
cryptography that occurred in the 70’s.
This cryptosystem was developed in the 70’s by
IBM, with help from the NSA, and lasted through
the 90’s.
This cryptosystem handles the majority of
worldwide cryptography today.
In the above cryptosystem, how many bits are
required in the key for “top secret” documents.
What is the “newest” cryptosystem we have talked
about?
6.
7.
8.
9.
10.
What country discovered RSA before it was known
publically?
What does DES stand for?
What does AES stand for?
What does RSA stand for?
What does ECC stand for?
1.
2.
3.
4.
5.
Encrypt 2 in the RSA system with 𝑛 = 21 and 𝑏 = 8.
S 0 1 2 3
Decrypt 5 in the same RSA system.
0 a b c d
Run 13 through the S-box.
1 e f g h
Find 4 points on E2,1 ℤ5
2 i j k l
Find the slope of the line connecting 2,3 and 6,8
6.
7.
8.
9.
10.
Find the equation for the line containing 0,4 and
1,7 .
How many squares are there in ℤ11 ?
Find an upper bound on the number of points on
E5,8 ℤ37 .
Perform the “shift rows” operation from AES on the
accompanying AES message.
Perform the “mix columns” operation on the
accompanying column.
0x01
0 1 2 3
0x00
4
5
6
7
0x00
8
9
A B
0x00
C D E F
1.
2.
3.
What is the value of A?
What is the value of B?
What is the value of C?
A = 5;
B = 3;
C = A + B * B;
4.
5.
What is the value of A?
What is the value of B?
A = 5;
B = A;
A = 4;
6.
7.
How many multiplications are used in the following
program?
What is the value of A?
A = 2;
Count = 1;
While(Count < 4)
A = A * A;
End
8.
9.
How many multiplications are used in the following
program?
What is the value of A?
A = 1;
While(A < 2^3)
A = A * 2;
End
10.
True or false: A = B
A = 5;
B = A;
A = 4;
1.
2.
3.
4.
5.
Which of these encrypt the slowest? DES, AES, RSA,
ECC.
Why is AES preferred to DES?
Why is ECC preferred to RSA?
AES consists of 4 operations: xor’ing a key, mixing
columns, S-box substitution, and _____________.
How is the DES S-box and AES S-box fundamentally
different?
6.
7.
8.
9.
10.
RSA and ECC have _________ security.
AES has __________ security.
DES has __________ security.
Which would be more secure? RSA built from two
64-bit primes, or RSA built from four 32-bit primes?
Which of these would require the most operations to
encrypt one message? 128-bit AES, 128-bit RSA, or
128-bit ECC?
The End
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Created in the summer of 2013 by Dr. Jeffrey
Beyerl for use in a cryptography class.
This is just a vanilla PowerPoint, but of course
like anything you download from the internet:
use at your own risk.