elliptic-curve

问题 Is there some way to enumerate all of the elliptic curve names that can be given to the ECGenParameterSpec constructor? Or do you have to just throw a big list of curve names at the wall and see which ones do or don't throw execeptions when you try to use them? 回答1: It depends very much on the provider you want to use. As stated by user69513, you'll want to consult the documentation. And there lies the most basic of problems. For the SunEC provider, the documentation is nowhere to be found,

问题 I am trying to generate a signature using ECDSA with SHA256 in Bouncy Castle as follows, I add the provider in the begining I have built the ECPrivatekey Signature s_oSignature = Signature.getInstance("SHA256withECDSA", BouncyCastleProvider.PROVIDER_NAME); but step 3 throws "java.security.NoSuchAlgorithmException: no such algorithm: SHA256withECDSA for provider BC" . But same "SHA256withECDSA" thing when replaced with "SHA1withECDSA" prceeds without any exception. How is it possible? I am

问题 I am trying to generate a signature using ECDSA with SHA256 in Bouncy Castle as follows, I add the provider in the begining I have built the ECPrivatekey Signature s_oSignature = Signature.getInstance("SHA256withECDSA", BouncyCastleProvider.PROVIDER_NAME); but step 3 throws "java.security.NoSuchAlgorithmException: no such algorithm: SHA256withECDSA for provider BC" . But same "SHA256withECDSA" thing when replaced with "SHA1withECDSA" prceeds without any exception. How is it possible? I am

问题 I am trying to generate a signature using ECDSA with SHA256 in Bouncy Castle as follows, I add the provider in the begining I have built the ECPrivatekey Signature s_oSignature = Signature.getInstance("SHA256withECDSA", BouncyCastleProvider.PROVIDER_NAME); but step 3 throws "java.security.NoSuchAlgorithmException: no such algorithm: SHA256withECDSA for provider BC" . But same "SHA256withECDSA" thing when replaced with "SHA1withECDSA" prceeds without any exception. How is it possible? I am

问题 I am trying to generate a signature using ECDSA with SHA256 in Bouncy Castle as follows, I add the provider in the begining I have built the ECPrivatekey Signature s_oSignature = Signature.getInstance("SHA256withECDSA", BouncyCastleProvider.PROVIDER_NAME); but step 3 throws "java.security.NoSuchAlgorithmException: no such algorithm: SHA256withECDSA for provider BC" . But same "SHA256withECDSA" thing when replaced with "SHA1withECDSA" prceeds without any exception. How is it possible? I am

问题 I'm trying to figure out the most simple way to digitally sign a string of hex values using a private key also represented by a string of hex values. I'm open to command line, or a script, but preferably using openssl cli. Example: string to sign: 1333183ddf384da83ed49296136c70d206ad2b19331bf25d390e69b222165e37 private key: a675c86089e0622c112379906f5cf19ee336575af1bfa1de558051312db9afdc Hoping there is a command like: $ openssl sign -msg

问题 #include "include/cryptopp/oids.h" #include "include/cryptopp/eccrypto.h" #include <cstdio> #include <iostream> using namespace std; using namespace CryptoPP; void init() { ECDH<ECP>::Domain ecdhc(ASN1::secp256k1()); auto g_p = ecdhc.GetGroupParameters(); auto g_ec = g_p.GetSubgroupGenerator(); auto g_ec_ = g_p.GetCurve().Subtract(g_p.GetCurve().Add(g_ec, g_ec), g_ec); if(g_p.GetCurve().Equal(g_ec_, g_ec)) printf("P\n"); else printf("NP\n"); } int main() { init(); return 0; } As an example

问题 It seems that .NET (Core 3.1) supports custom curves in ECC. So I've defined the Curve25519, and generated key pair by below code: using System; using System.Security.Cryptography; namespace Curve25519 { class Program { static void Main(string[] args) { ECCurve ecCurve = new ECCurve() // Curve25519, 32 bytes, 256 bit { CurveType = ECCurve.ECCurveType.PrimeMontgomery, B = new byte[] { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 }, A = new byte

来源： https://stackoverflow.com/questions/64862815/how-to-decompress-x9-62-coordinate

来源： https://stackoverflow.com/questions/64862815/how-to-decompress-x9-62-coordinate