Evaluating the SHA-256 and Elliptic Curve Digital Signature
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8/13/2019 Evaluating the SHA-256 and Elliptic Curve Digital Signature
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Evaluating the SHA-256 and Elliptic
Curve Digital Signature Algorithmsin Bitcoin Transactions
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Overview
What is a Bitcoin?
How do I get Bitcoins?
Bitcoin transactions SHA-256
ECDSA
Current price Q/A
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How do I get Bitcoins?
21-million Bitcoins
Designed to be an obtainable resource
Must be mined
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The Mint
Central authority that checksevery transaction
Contradictory?
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Secure Hash Algorithm
Designed by the U.S. National Security Agency
(NSA)
Transforms set of data elements into a fixed-
length value.
Verifies integrity of copies without needing to
derive original data
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SHA-256
Define
Preprocessing1. Append the bit 1 to the end of the message, followed by kzero bits, where kis the smallest non-negative solution to the
equation:
2. Parse the padded message intoN512-bit blocks:
3. The initial values of eight 32-bit words are initialized to the first 32 bits of the fractional parts of the square roots of the first
eight prime numbers:
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SHA-256 cont.
Steps:
1. The message schedule is prepared according to the equation:
2. Initialize the eight 32-bit working variables:
3. Perform the compression function for t = 0 to 63:
4. Compute the intermediate hash:
Final Hash:
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SHA Example
ASCII string: abc 448(24 + 1) =
Hex Representation:
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SHA Example Cont.
SHA-256 initial hash value:
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Elliptic Curve Digital Signature Algorithm
Public-key pairs
Key generation
Signature generation Signature verification
Weaknesses
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Signature Generation
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Signature Verification
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References
http://spectrum.ieee.org/computing/software
/bitcoin-the-cryptoanarchists-answer-to-cash
http://spectrum.ieee.org/computing/software/bitcoin-the-cryptoanarchists-answer-to-cashhttp://spectrum.ieee.org/computing/software/bitcoin-the-cryptoanarchists-answer-to-cashhttp://spectrum.ieee.org/computing/software/bitcoin-the-cryptoanarchists-answer-to-cashhttp://spectrum.ieee.org/computing/software/bitcoin-the-cryptoanarchists-answer-to-cashhttp://spectrum.ieee.org/computing/software/bitcoin-the-cryptoanarchists-answer-to-cashhttp://spectrum.ieee.org/computing/software/bitcoin-the-cryptoanarchists-answer-to-cashhttp://spectrum.ieee.org/computing/software/bitcoin-the-cryptoanarchists-answer-to-cashhttp://spectrum.ieee.org/computing/software/bitcoin-the-cryptoanarchists-answer-to-cashhttp://spectrum.ieee.org/computing/software/bitcoin-the-cryptoanarchists-answer-to-cashhttp://spectrum.ieee.org/computing/software/bitcoin-the-cryptoanarchists-answer-to-cashhttp://spectrum.ieee.org/computing/software/bitcoin-the-cryptoanarchists-answer-to-cashhttp://spectrum.ieee.org/computing/software/bitcoin-the-cryptoanarchists-answer-to-cashhttp://spectrum.ieee.org/computing/software/bitcoin-the-cryptoanarchists-answer-to-cashhttp://spectrum.ieee.org/computing/software/bitcoin-the-cryptoanarchists-answer-to-cash
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