Re: [viff-devel] Equality protocol : error
I know this is talking around the problem but: For very small moduli like yours, another protocol for equality is actually simpler, better (no risk of failing) and faster (I guess): raise (a-b) to n-1 (with square and multiply), and if this difference was 0 you will get 0, otherwise you will get 1 (good old fermat), this result can be subtracted from 1, to turn the bit correctly. I actually coded this once, but for some reason I never got to put it into Viff I have attached a patch you can try to apply (use hg qimport fermatequality, hg qpush), and play with for now. I will try to look into the real bug later. The best Sigurd On Thu, Apr 8, 2010 at 11:34 PM, Marcel Keller wrote: > Hi Jonathan, > > I can't reproduce the error here. Can you send me your config files? The > error might be triggered by certain random numbers, which depend on the PRSS > keys. By the way, the error message is about the same every time something > goes wrong in a callback. This is because VIFF does not define errbacks. To > get a little bit more meaningful output, you can use the --deferred-debug > parameter. > > Best regards, > Marcel > fermatequality Description: Binary data ___ viff-devel mailing list (http://viff.dk/) viff-devel@viff.dk http://lists.viff.dk/listinfo.cgi/viff-devel-viff.dk
Re: [viff-devel] Equality protocol : error
Hi Jonathan, I can't reproduce the error here. Can you send me your config files? The error might be triggered by certain random numbers, which depend on the PRSS keys. By the way, the error message is about the same every time something goes wrong in a callback. This is because VIFF does not define errbacks. To get a little bit more meaningful output, you can use the --deferred-debug parameter. Best regards, Marcel ___ viff-devel mailing list (http://viff.dk/) viff-devel@viff.dk http://lists.viff.dk/listinfo.cgi/viff-devel-viff.dk
Re: [viff-devel] Equality protocol : error
Dear Ivan,
Yes I know about that. But 367 is 3 mod 4 so it should be OK. And the existing
protocol works with 367 only if the two numbers are not equal. If they are, I
got the error mentioned in my first message.
If I can solve the error in the existing protocol, I will be able to continue
my work.
Thank you for your answer,
Jonathan
Le 8 avr. 2010 à 16:26, Ivan Damgård a écrit :
> Dear Jonathan,
>
> You cannot expect the protocol to work for primes that are 1 mod 4,
> it is based on the fact that for primes p that are 3 mod 4, you can
> deterministically
> compute a square root mod p by raising to power (p+1)/4.
> This does not work if p is 1 mod 4.
>
> regards, Ivan
>
> On 08/04/2010, at 14.11, Jonathan Van den Schrieck wrote:
>
>> Hello,
>>
>> I am trying to modify the equality protocol to make it work for primes
>> congruent to 5 mod 8 (exists for Blum primes).
>> The problem is that I have an error with the original protocol. It works
>> perfectly with p = 211 for example. But for p = 367, it doesn't.
>> Here is the code I'm using to test it :
>>
>> from optparse import OptionParser
>> import viff.reactor
>> viff.reactor.install()
>> from twisted.internet import reactor
>> from viff.field import GF
>> from viff.runtime import create_runtime, gather_shares
>> from viff.passive import PassiveRuntime
>> from viff.equality_ohta import ProbabilisticEqualityMixin2
>> from viff.equality import ProbabilisticEqualityMixin
>> from viff.comparison import Toft05Runtime
>> from viff.config import load_config
>> from viff.util import rand, find_prime
>>
>> class EqualityRuntime(PassiveRuntime, ProbabilisticEqualityMixin):
>> """Default mix of :class:`~viff.equality.ProbabilisticEqualityMixin`
>> and :class:`~viff.passive.PassiveRuntime`.
>> """
>> pass
>>
>> class Protocol:
>>
>> def __init__(self, runtime):
>> # Save the Runtime for later use
>> self.runtime = runtime
>> k = runtime.options.security_parameter
>> print "security parameter = ", k
>> Zp = GF(367)
>>
>> # We must secret share our input with the other parties. They
>> # will do the same and we end up with three variables
>> # input is equal to the player id
>>
>> rand = runtime.prss_share_random(Zp)
>> #rand1 = runtime.prss_share_random(Zp)
>> rand1 = rand
>> print "rand = ", rand, "rand1 = ", rand1
>>
>> #open rand and rand1 to print their value
>> open_rand = runtime.open(rand)
>> open_rand1 = runtime.open(rand1)
>> temp = gather_shares([open_rand, open_rand1])
>> temp.addCallback(self.results_ready)
>>
>> # we test if rand == rand1 by using equality protocol
>> test = (rand == rand1)
>> test_open = runtime.open(test)
>> results = gather_shares([test_open])
>> results.addCallback(self.results_ready)
>>
>> runtime.schedule_callback(results, lambda _: runtime.synchronize())
>> runtime.schedule_callback(results, lambda _: runtime.shutdown())
>>
>> def results_ready(self, results):
>> print "ALGO_QUAD temp results =", results
>>
>>
>> def mtemp(self, temp):
>> print "local part of shares after callback ="
>> print temp
>>
>>
>> # Parse command line arguments.
>> parser = OptionParser()
>> EqualityRuntime.add_options(parser)
>> options, args = parser.parse_args()
>>
>> if len(args) == 0:
>> parser.error("you must specify a config file")
>> else:
>> id, players = load_config(args[0])
>>
>> # Create a deferred Runtime and ask it to run our protocol when ready.
>> pre_runtime = create_runtime(id, players, 1, options, EqualityRuntime)
>> pre_runtime.addCallback(Protocol)
>>
>> # Start the Twisted event loop.
>> reactor.run()
>>
>> as you can see, I simply generate 2 random numbers, then I test if they have
>> the same value, and I print the result of the test.
>> This will work if rand != rand1, but if I set rand1 = rand => ERROR.
>> This error will only happen if p = 367 (and maybe with others primes, but I
>> couldn't test them all)
>> Here is the error :
>>
>> Unhandled error in Deferred:
>> Traceback (most recent call last):
>> File
>> "/System/Library/Frameworks/Python.framework/Versions/2.5/Extras/lib/python/twisted/internet/defer.py",
>> line 328, in _runCallbacks
>> self.result = callback(self.result, *args, **kw)
>> File "/Users/jonathanvds/opt/lib/python/viff/runtime.py", line 239, in
>> _callback_fired
>> self.callback(self.results)
>> File
>> "/System/Library/Frameworks/Python.framework/Versions/2.5/Extras/lib/python/twisted/internet/defer.py",
>> line 243, in callback
>> self._startRunCallbacks(result)
>> File
>> "/System/Library/Frameworks/Python.framework/Versions/2.5/Extras/lib/python/twisted/internet/defer.py",
>> line 312, in _startRunCallbacks
>> self._runCallbacks()
>> --- ---
>> File
>> "/
Re: [viff-devel] Equality protocol : error
Dear Jonathan,
You cannot expect the protocol to work for primes that are 1 mod 4,
it is based on the fact that for primes p that are 3 mod 4, you can
deterministically
compute a square root mod p by raising to power (p+1)/4.
This does not work if p is 1 mod 4.
regards, Ivan
On 08/04/2010, at 14.11, Jonathan Van den Schrieck wrote:
Hello,
I am trying to modify the equality protocol to make it work for
primes congruent to 5 mod 8 (exists for Blum primes).
The problem is that I have an error with the original protocol. It
works perfectly with p = 211 for example. But for p = 367, it doesn't.
Here is the code I'm using to test it :
from optparse import OptionParser
import viff.reactor
viff.reactor.install()
from twisted.internet import reactor
from viff.field import GF
from viff.runtime import create_runtime, gather_shares
from viff.passive import PassiveRuntime
from viff.equality_ohta import ProbabilisticEqualityMixin2
from viff.equality import ProbabilisticEqualityMixin
from viff.comparison import Toft05Runtime
from viff.config import load_config
from viff.util import rand, find_prime
class EqualityRuntime(PassiveRuntime, ProbabilisticEqualityMixin):
"""Default mix
of :class:`~viff.equality.ProbabilisticEqualityMixin`
and :class:`~viff.passive.PassiveRuntime`.
"""
pass
class Protocol:
def __init__(self, runtime):
# Save the Runtime for later use
self.runtime = runtime
k = runtime.options.security_parameter
print "security parameter = ", k
Zp = GF(367)
# We must secret share our input with the other parties. They
# will do the same and we end up with three variables
# input is equal to the player id
rand = runtime.prss_share_random(Zp)
#rand1 = runtime.prss_share_random(Zp)
rand1 = rand
print "rand = ", rand, "rand1 = ", rand1
#open rand and rand1 to print their value
open_rand = runtime.open(rand)
open_rand1 = runtime.open(rand1)
temp = gather_shares([open_rand, open_rand1])
temp.addCallback(self.results_ready)
# we test if rand == rand1 by using equality protocol
test = (rand == rand1)
test_open = runtime.open(test)
results = gather_shares([test_open])
results.addCallback(self.results_ready)
runtime.schedule_callback(results, lambda _:
runtime.synchronize())
runtime.schedule_callback(results, lambda _:
runtime.shutdown())
def results_ready(self, results):
print "ALGO_QUAD temp results =", results
def mtemp(self, temp):
print "local part of shares after callback ="
print temp
# Parse command line arguments.
parser = OptionParser()
EqualityRuntime.add_options(parser)
options, args = parser.parse_args()
if len(args) == 0:
parser.error("you must specify a config file")
else:
id, players = load_config(args[0])
# Create a deferred Runtime and ask it to run our protocol when ready.
pre_runtime = create_runtime(id, players, 1, options, EqualityRuntime)
pre_runtime.addCallback(Protocol)
# Start the Twisted event loop.
reactor.run()
as you can see, I simply generate 2 random numbers, then I test if
they have the same value, and I print the result of the test.
This will work if rand != rand1, but if I set rand1 = rand => ERROR.
This error will only happen if p = 367 (and maybe with others
primes, but I couldn't test them all)
Here is the error :
Unhandled error in Deferred:
Traceback (most recent call last):
File "/System/Library/Frameworks/Python.framework/Versions/2.5/
Extras/lib/python/twisted/internet/defer.py", line 328, in
_runCallbacks
self.result = callback(self.result, *args, **kw)
File "/Users/jonathanvds/opt/lib/python/viff/runtime.py", line
239, in _callback_fired
self.callback(self.results)
File "/System/Library/Frameworks/Python.framework/Versions/2.5/
Extras/lib/python/twisted/internet/defer.py", line 243, in callback
self._startRunCallbacks(result)
File "/System/Library/Frameworks/Python.framework/Versions/2.5/
Extras/lib/python/twisted/internet/defer.py", line 312, in
_startRunCallbacks
self._runCallbacks()
--- ---
File "/System/Library/Frameworks/Python.framework/Versions/2.5/
Extras/lib/python/twisted/internet/defer.py", line 328, in
_runCallbacks
self.result = callback(self.result, *args, **kw)
File "/Users/jonathanvds/opt/lib/python/viff/passive.py", line
211, in
result.addCallback(lambda (a, b): a * b)
exceptions.TypeError: unsupported operand type(s) for *: 'instance'
and 'GFElement'
I can't find where the problem comes from since I only have the
error with p = 367 (and I have the same error with my new protocol
for p = 5 mod 8, but I'm guessing that if I can solve the problem
in the existing protocol, I'll be able to do the same with my
implementation).
Thank you for your help,
Jonathan Van den Schrieck
__
[viff-devel] Equality protocol : error
Hello,
I am trying to modify the equality protocol to make it work for primes
congruent to 5 mod 8 (exists for Blum primes).
The problem is that I have an error with the original protocol. It works
perfectly with p = 211 for example. But for p = 367, it doesn't.
Here is the code I'm using to test it :
from optparse import OptionParser
import viff.reactor
viff.reactor.install()
from twisted.internet import reactor
from viff.field import GF
from viff.runtime import create_runtime, gather_shares
from viff.passive import PassiveRuntime
from viff.equality_ohta import ProbabilisticEqualityMixin2
from viff.equality import ProbabilisticEqualityMixin
from viff.comparison import Toft05Runtime
from viff.config import load_config
from viff.util import rand, find_prime
class EqualityRuntime(PassiveRuntime, ProbabilisticEqualityMixin):
"""Default mix of :class:`~viff.equality.ProbabilisticEqualityMixin`
and :class:`~viff.passive.PassiveRuntime`.
"""
pass
class Protocol:
def __init__(self, runtime):
# Save the Runtime for later use
self.runtime = runtime
k = runtime.options.security_parameter
print "security parameter = ", k
Zp = GF(367)
# We must secret share our input with the other parties. They
# will do the same and we end up with three variables
# input is equal to the player id
rand = runtime.prss_share_random(Zp)
#rand1 = runtime.prss_share_random(Zp)
rand1 = rand
print "rand = ", rand, "rand1 = ", rand1
#open rand and rand1 to print their value
open_rand = runtime.open(rand)
open_rand1 = runtime.open(rand1)
temp = gather_shares([open_rand, open_rand1])
temp.addCallback(self.results_ready)
# we test if rand == rand1 by using equality protocol
test = (rand == rand1)
test_open = runtime.open(test)
results = gather_shares([test_open])
results.addCallback(self.results_ready)
runtime.schedule_callback(results, lambda _: runtime.synchronize())
runtime.schedule_callback(results, lambda _: runtime.shutdown())
def results_ready(self, results):
print "ALGO_QUAD temp results =", results
def mtemp(self, temp):
print "local part of shares after callback ="
print temp
# Parse command line arguments.
parser = OptionParser()
EqualityRuntime.add_options(parser)
options, args = parser.parse_args()
if len(args) == 0:
parser.error("you must specify a config file")
else:
id, players = load_config(args[0])
# Create a deferred Runtime and ask it to run our protocol when ready.
pre_runtime = create_runtime(id, players, 1, options, EqualityRuntime)
pre_runtime.addCallback(Protocol)
# Start the Twisted event loop.
reactor.run()
as you can see, I simply generate 2 random numbers, then I test if they have
the same value, and I print the result of the test.
This will work if rand != rand1, but if I set rand1 = rand => ERROR.
This error will only happen if p = 367 (and maybe with others primes, but I
couldn't test them all)
Here is the error :
Unhandled error in Deferred:
Traceback (most recent call last):
File
"/System/Library/Frameworks/Python.framework/Versions/2.5/Extras/lib/python/twisted/internet/defer.py",
line 328, in _runCallbacks
self.result = callback(self.result, *args, **kw)
File "/Users/jonathanvds/opt/lib/python/viff/runtime.py", line 239, in
_callback_fired
self.callback(self.results)
File
"/System/Library/Frameworks/Python.framework/Versions/2.5/Extras/lib/python/twisted/internet/defer.py",
line 243, in callback
self._startRunCallbacks(result)
File
"/System/Library/Frameworks/Python.framework/Versions/2.5/Extras/lib/python/twisted/internet/defer.py",
line 312, in _startRunCallbacks
self._runCallbacks()
--- ---
File
"/System/Library/Frameworks/Python.framework/Versions/2.5/Extras/lib/python/twisted/internet/defer.py",
line 328, in _runCallbacks
self.result = callback(self.result, *args, **kw)
File "/Users/jonathanvds/opt/lib/python/viff/passive.py", line 211, in
result.addCallback(lambda (a, b): a * b)
exceptions.TypeError: unsupported operand type(s) for *: 'instance' and
'GFElement'
I can't find where the problem comes from since I only have the error with p =
367 (and I have the same error with my new protocol for p = 5 mod 8, but I'm
guessing that if I can solve the problem in the existing protocol, I'll be able
to do the same with my implementation).
Thank you for your help,
Jonathan Van den Schrieck
___
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