Hi Partch, I'll take this one Wei ;)
> Unfortunately, this doesn't seem to be implemented Correct, but it is not a Crypto++ limitation. See http://groups.google.com/group/cryptopp-users/browse_thread/thread/36c7408fa837abaf/# > Firstly, I wonder if there is any special reasons for not > implementing it, or is it just on the to do list? Referring to Handbook of Applied Cryptography (http://www.cacr.math.uwaterloo.ca/hac/), there is no such beast. > But it seems like ECDSA is set up to do its own hashing by > default (is it using SHA?). If I recall, ECDSA use SHA1 (160 bits). See eccrypto.h and eccrypto.cpp. Perhaps the following may be of help for finding samples for use in your system: http://www.cryptopp.com/wiki/External_Samples Jeff On 6/12/07, Parch <[EMAIL PROTECTED]> wrote: > > Hi, > I am new to using Crypto++, enjoying the puzzle of figuring out how it > all works. I have a couple questions about best use of ECDSA. > > I am thinking of using the digital signatures with elliptic curves for > a product licensing scheme. I just tried to do ECDSA with message > recovery. Unfortunately, this doesn't seem to be implemented. Firstly, > I wonder if there is any special reasons for not implementing it, or > is it just on the to do list? Secondly, I wonder how to solve my real > problem. Let me explain what I was attempting: > > When I wrote this code, I was considering transmitting recoverable > plaintext, but I was originally considering sending half of the > plaintext (the other half is read from the local machine, and must be > shared between parties prior to licensing), hashing the plaintext > parts together, and then using ECDSA to encrypt that hash to produce a > signature to send with the half plaintext. But it seems like ECDSA is > set up to do its own hashing by default (is it using SHA?). > > Am I getting tangled up because I assumed I would be able to compare > plain-texts, with verification, where in fact I could be comparing > hashes, and using the ECDSA Signer/Verifier in a much simpler way? > > And finally Wei Dai, this library is amazing. I would enjoy reading > general stuff about your education, how you learned to write amazing C+ > + code, why you designed Crypto++ this way, and so on. > > thanks, > Parch --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the "Crypto++ Users" Google Group. To unsubscribe, send an email to [EMAIL PROTECTED] More information about Crypto++ and this group is available at http://www.cryptopp.com. -~----------~----~----~----~------~----~------~--~---
