/[gzz]/manuscripts/Sigs/article.rst
ViewVC logotype

Diff of /manuscripts/Sigs/article.rst

Parent Directory Parent Directory | Revision Log Revision Log | View Patch Patch

revision 1.128 by tjl, Mon May 19 19:03:39 2003 UTC revision 1.129 by benja, Mon May 19 19:26:00 2003 UTC
# Line 32  We discuss two example instances: Line 32  We discuss two example instances:
32  a high-security instance with  a high-security instance with
33  unlimited use, 160-bit security,  unlimited use, 160-bit security,
34  which requires  which requires
35  a 110 KB signature, 175'072 hash invocations for signing, and  a 110 KB signature, 201'952 hash function invocations for signing, and
36  5'568 hash invocations for verification.  5'568 hash invocations for verification.
37  On a more practical level, we discuss a  On a more practical level, we discuss a
38  probabilistically valid instance with 56-bit security  probabilistically valid instance with 56-bit security
39  if only used for up to XXX signatures.  if only used for up to XXX signatures.
40  The probabilistic scheme requires  The probabilistic scheme requires
41  a 28 KB sig, 175'096 hash invocations for signing, 1'408 hashes  a 42 KB sig, 75'732 hash invocations for signing, and 2'088 hashes
42  for verification.  for verification.
43    
44  Introduction  Introduction
# Line 250  For example, Line 250  For example,
250    
251      - impractical; actual numbers below      - impractical; actual numbers below
252    
253        - With key_boosting(32, merkle_hashtree(5, merkleI(160, 160)))::        - With key_boosting_real(32, 5, 160)::
254    
255            (q=2^160.0, b=160, s=110.0 KB, r=20 B, h=20 B,            (q=2^160.0, b=160, s=110.0 KB,
256             t0=5.47e+03 [~27.355ms], ts=1.75e+05 [~875.36ms],            r=20 B, h=20 B,
257             tv=5.57e+03 [~27.84ms])            t0=6.31e+03 [~31.555ms],
258              ts=2.02e+05 [~1009.76ms],
259              tv=5.57e+03 [~27.84ms])
260    
261    The private keys in these schemes is only 160 bits long;
262    the random oracle is used to generate all the other private keys.
263    
264    
265  - Maybe also mention:  - Maybe also mention:
# Line 276  In practice, it may be useful to relax t Line 281  In practice, it may be useful to relax t
281  requirements somewhat to obtain more practical schemes.  requirements somewhat to obtain more practical schemes.
282    
283  - For smaller sigs and faster verification,  - For smaller sigs and faster verification,
284    key_boosting(8, merkle_hashtree(7, merkleI(160, 160)))::    key_boosting_real(8, 7, 160)::
285    
286      (q=2^56.0, b=160, s=27.8125 KB, r=20 B, h=20 B,      (q=2^56.0, b=160, s=27.8125 KB,
287      t0=2.19e+04 [~109.435ms], ts=1.75e+05 [~875.48ms],       r=20 B, h=20 B,
288      tv=1.41e+03 [~7.04ms])       t0=2.31e+04 [~115.315ms],
289         ts=1.85e+05 [~922.52ms],
290         tv=1.41e+03 [~7.04ms])
291    
292  - For faster signing,  - For faster signing,
293    key_boosting(12, merkle_hashtree(5, merkleI(160, 160)))::    key_boosting_real(12, 5, 160)::
294    
295      (q=2^60.0, b=160, s=41.25 KB, r=20 B, h=20 B,      (q=2^60.0, b=160, s=41.25 KB,
296      t0=5.47e+03 [~27.355ms], ts=6.57e+04 [~328.26ms],       r=20 B, h=20 B,
297      tv=2.09e+03 [~10.44ms])       t0=6.31e+03 [~31.555ms],
298         ts=7.57e+04 [~378.66ms],
299         tv=2.09e+03 [~10.44ms])
300    
301  This may be ok when using up to a million or so random keys  This may be ok when using up to a million or so random keys
302  (XXX chance of a common birthday then?)  (XXX chance of a common birthday then?)
# Line 295  This may be ok when using up to a millio Line 304  This may be ok when using up to a millio
304  It is also possible to use key boosting to form `$k$`-time  It is also possible to use key boosting to form `$k$`-time
305  signature schemes for large `$k$`. For example, for `$k=2^20$`:  signature schemes for large `$k$`. For example, for `$k=2^20$`:
306    
307  - key_boosting(5, merkle_hashtree(4, merkleI(160, 160)))::  - key_boosting_real(5, 4, 160)::
308    
309      (q=2^20.0, b=160, s=17.08984375 KB, r=20 B, h=20 B,      (q=2^20.0, b=160, s=17.08984375 KB,
310      t0=2.74e+03 [~13.675ms], ts=1.37e+04 [~68.375ms],       r=20 B, h=20 B,
311      tv=8.65e+02 [~4.325ms])       t0=3.41e+03 [~17.035ms],
312         ts=1.70e+04 [~85.175ms],
313         tv=8.65e+02 [~4.325ms])
314    
315  Of course, there is the common technique to create a tree  Of course, there is the common technique to create a tree
316  of one-time signatures, where each key at the top signs  of one-time signatures, where each key at the top signs

Legend:
Removed from v.1.128  
changed lines
  Added in v.1.129

savannah-hackers-public@gnu.org
ViewVC Help
Powered by ViewVC 1.1.26