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Reyzin |
Reyzin |
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------ |
------ |
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We discuss only the second algorithm, based on subset-intractable |
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functions. |
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To sign `$b$` bits, choose `$t$` and `$k$` such that |
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`$ {t \choose k} \ge b $` |
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Parameters `$t$` and `$k$`. |
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- private key: `$t$` random numbers |
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- public key: hashes of the random numbers. Calculate `$t$` hashes |
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- sign: Hash the message, split hash to `$k$` strings of `$\\log t$` bits. |
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use these as indices to say which numbers to reveal in the signature. |
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Calculate one hash. |
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- verify: same deterministic part, check that revealed numbers hash right. |
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Probability for successful forgery after `$r$` signatures: |
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`$(rk/t)^k$` |
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? |
? |
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Bleichenbacher-Maurer |
Bleichenbacher-Maurer |
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\parbox{\sw}{BiBa $(h,b,q,n,t,w)$} |
\parbox{\sw}{BiBa $(h,b,q,n,t,w)$} |
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& $q$ & $b$ & $th$ & $wh$ & $h$ & $t$ & $?+wh$ & $w$ \\ |
& $q$ & $b$ & $th$ & $wh$ & $h$ & $t$ & $?+wh$ & $w$ \\ |
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\parbox{\sw}{Reyzin one-way\cite{XXX} $(h,b,t,k)$ } |
\parbox{\sw}{Reyzin one-way\cite{XXX} $(h,b,t,k)$ } |
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& $1$ & $b$ & $kh$ & $h$ & $h$ & $t$ & $?$ & $?+k$ \\ |
& $1$ & $b$ & $kh$ & $th$ & $h$ & $t$ & $1$ (XXX) & $1+k$ (XXX) \\ |
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olean mouseClickHit(MouseEvent e, VobScene oldVobScene, float[] zout); |
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\parbox{\sw}{Bleichenbacher-Maurer\cite{XXX (ASIACRYPT)} |
\parbox{\sw}{Bleichenbacher-Maurer\cite{XXX (ASIACRYPT)} |
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(h, n) |
(h, n) |
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} |
} |