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| Here are the questions in Mathematics » Cryptography. Go get 'em! 1-8 of 8
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Due |
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| $20.00 |
Unanswered |
Cryptography - Discrete Log as One Way Function
Cryptography - Given that Discrete Log function is at least weak one-way function, need to show that it is a [strong] One Way Function. Full question in the attachement.
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Dec. 02, 2008 |
| $20.00 |
Unanswered |
Hardness amplification of Weak One-Way Functions - Cryptography
This is a class practice question on Hardness Amplification of One-Way Functions that I did not get. Pointing to the supporting material would also be appreciated. The term 'Shekels' refers to a...
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Dec. 02, 2008 |
| $10.00 |
Unanswered |
Please help with this Cryptography problem
Alice wants to use the El Gamal Signature Scheme. She chooses an initial value (randomly) k_0. She then uses the value k_i to sign the ith message, where k_i = k_0 + 2i mod (p-1). (Therefore, k_i =...
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Dec. 01, 2008 |
| $10.00 |
Unanswered |
Please help with this Cryptography problem
i) An El Gamal Signature Scheme or Digital Signature Algorithm signature isn't allowed to have delta = 0. Show that it would be easy for Oscar to compute the secret key, a, if a message were signed...
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Dec. 01, 2008 |
| $10.00 |
Unanswered |
Please help me out with this Cryptography problem
i) In describing a potential attack against Digital Signature Algorithm, spoz x is known and let z = (SHA-1(x))^{-1} mod q and epsilon = beta^z mod p. Now spoz it's possible to determine gamma,...
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Dec. 01, 2008 |
| $10.00 |
Answered |
Please help me out with this Cryptography problem
Let h_1 : {0,1}^(2m) -> {0,1}^m be a collision-resistant hash function. Also let || represent concatenation. Define h_i : {0,1}^((2^i)m) -> {0,1}^m recursively from h_{i-1}, as follows (i is...
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Nov. 19, 2008 |
| $15.00 |
Answered |
Please help me out with this Cryptography problem
Let h: X -> Y be a (N,M) hash function. or any y \in Y, let h^{-1}(y) = {x: h(x) = y } and denote s_y = |h^{-1}(y)|. Also let S = |{{x_1, x_2} : h(x_1) = h(x_2)}|. (S counts the unordered...
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Nov. 19, 2008 |
| $10.00 |
Answered |
Please help me understand this Cryptography question
a) Suppose that n = m > 1 and h: Z_{2^m} -> Z_{2^m} is defined as: h(x) = x^2 + ax + b mod 2^m Prove that it is easy to solve the second pre-image problem for any x \in Z_{2^m} without having...
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Nov. 18, 2008 |
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