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[Gzz-commits] manuscripts/Sigs article.rst poss.py
From: |
Tuomas J. Lukka |
Subject: |
[Gzz-commits] manuscripts/Sigs article.rst poss.py |
Date: |
Sun, 18 May 2003 15:47:11 -0400 |
CVSROOT: /cvsroot/gzz
Module name: manuscripts
Changes by: Tuomas J. Lukka <address@hidden> 03/05/18 15:47:11
Modified files:
Sigs : article.rst poss.py
Log message:
scheme
CVSWeb URLs:
http://savannah.gnu.org/cgi-bin/viewcvs/gzz/manuscripts/Sigs/article.rst.diff?tr1=1.93&tr2=1.94&r1=text&r2=text
http://savannah.gnu.org/cgi-bin/viewcvs/gzz/manuscripts/Sigs/poss.py.diff?tr1=1.6&tr2=1.7&r1=text&r2=text
Patches:
Index: manuscripts/Sigs/article.rst
diff -u manuscripts/Sigs/article.rst:1.93 manuscripts/Sigs/article.rst:1.94
--- manuscripts/Sigs/article.rst:1.93 Sun May 18 15:37:41 2003
+++ manuscripts/Sigs/article.rst Sun May 18 15:47:11 2003
@@ -531,9 +531,14 @@
?
+<<<<<<< article.rst
+- serious vulnerabilities with chosen-message multiple signatures,
+
+=======
Octuplet: `$(1, b, kh, th, h, t, 1, 1+k)$`
+>>>>>>> 1.93
Bleichenbacher-Maurer
---------------------
@@ -611,7 +616,10 @@
- biba:
- - Reyzin subset-resilient;
+ - Reyzin subset-resilient. The security requirement,
+ for a single signature, means that
+ `$\\log t \ge {160-\log k \over k}$`.
+ A suitable choise seems to be `$t=1024$`, `$k=24$`
- alternatively, the Reyzin theoretical construction may be used,
where the time spent is somewhat more but security depends
Index: manuscripts/Sigs/poss.py
diff -u manuscripts/Sigs/poss.py:1.6 manuscripts/Sigs/poss.py:1.7
--- manuscripts/Sigs/poss.py:1.6 Sun May 18 15:37:42 2003
+++ manuscripts/Sigs/poss.py Sun May 18 15:47:11 2003
@@ -2,6 +2,12 @@
import math
from math import log, log10, ceil
+def fact(x):
+ return reduce(lambda a, b: a*b, range(1, x+1), 1L)
+
+def choose(n, k):
+ return fact(n) / (fact(k)*fact(n-k))
+
def lamport(h, b):
return (1, b, b*h, 2*b*h, h, 2*b, 0, b)
- [Gzz-commits] manuscripts/Sigs article.rst poss.py, Tuomas J. Lukka, 2003/05/18
- [Gzz-commits] manuscripts/Sigs article.rst poss.py, Tuomas J. Lukka, 2003/05/18
- [Gzz-commits] manuscripts/Sigs article.rst poss.py, Benja Fallenstein, 2003/05/18
- [Gzz-commits] manuscripts/Sigs article.rst poss.py, Benja Fallenstein, 2003/05/18
- [Gzz-commits] manuscripts/Sigs article.rst poss.py,
Tuomas J. Lukka <=
- [Gzz-commits] manuscripts/Sigs article.rst poss.py, Tuomas J. Lukka, 2003/05/18
- [Gzz-commits] manuscripts/Sigs article.rst poss.py, Tuomas J. Lukka, 2003/05/19