Thank you for the answer on SHA. I was wondering how the compiler was picking a default algorithm, and after you said to check the source, I did again, and realised it was happening through a forward declare, something I hadn't seen for template structs before:
template <class EC, class H = SHA> struct ECDSA; I do not understand the 'no such beast' reference at all, is that an in joke to those who have read the book? Is it the to do list that isn't? Finally, the 3rd link was not very obviously useful, as I can find no example code for ECDSA itself in any of the links. thanks, Parch > Correct, but it is not a Crypto++ limitation. > Seehttp://groups.google.com/group/cryptopp-users/browse_thread/thread/36... > > > 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. -~----------~----~----~----~------~----~------~--~---
