1996-03-28 - Question about Blind Signature

Header Data

From: Chein-hsinLiu <r3506010@cml11.csie.ntu.edu.tw>
To: cypherpunks@toad.com
Message Hash: 5b9e575e6e8b7b9ec1836783cf6285899df6c9e25a70466cf73feba91e439970
Message ID: <199603281310.VAA23754@cml11.csie.ntu.edu.tw>
Reply To: N/A
UTC Datetime: 1996-03-28 13:19:10 UTC
Raw Date: Thu, 28 Mar 96 05:19:10 PST

Raw message

From: Chein-hsinLiu <r3506010@cml11.csie.ntu.edu.tw>
Date: Thu, 28 Mar 96 05:19:10 PST
To: cypherpunks@toad.com
Subject: Question about Blind Signature
Message-ID: <199603281310.VAA23754@cml11.csie.ntu.edu.tw>
MIME-Version: 1.0
Content-Type: text/plain


Hi!
I have some stupid question about how to implement blind signature.
I Know it works as follows:
If A wants B to sign X but donot know it is X, A can send
   X*PK(random)  : PK is public key of B
Then B signs on message:
  SK(X*PK(random)) ==> SK(X)*random
Then A can obtain SK(X) by SK(X)*random/random

My question is when I see how RSA encrypts using PKCS
The PKCS block is like this
 00 01 FF FF FF FF ... 00 input
Then SK(00 01 FF FF FF .. 00 input) .
If the input = X*PK(random)
then SK(00 01 FF FF FF .. 00 X*PK(random)) will not produce SK(X)*random
How to solve this??
Thanks!!





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