ecdsa

I am struggling with the creation of a ECDSA public key from a string representation of a public key i.e string devicePublicKey("86FB5EB3CA0507226BE7197058B9EC041D3A3758D9D9C91902ACA3391F4E58AEF13AFF63CC4EF68942B9B94904DC1B890EDBEABD16B992110624968E894E560E"); previously I found that I had to prefix this key with '04' so not sure if this is require this time? I am trying to generate it to use in verifying a signature string ecs04b2ExpSignature("0199E984CEC75DDCA7F1DDF6E53E2E67352A2BE38A4B66F8ED596606FAB983FF300CAA76DE88CED9D563A5C03E8F3A7C000780F3F2061C611E9AA0B18B460D77"); where the data to

I am attempting to use bouncy castle to generate ECDSA keys. The code seems to work fine from the Java perspective; but, when I dump the file and try to validate the data, OpenSSL does not like the format of the data. After some research, I figured that bouncy castle is encoding the private key as public key. Here is my Java code: public class Test { public static void main(String[] args) { Security.addProvider(new BouncyCastleProvider()); System.out.println("Starting..."); String name = "prime256v1"; try { KeyPairGenerator kpg = KeyPairGenerator.getInstance("ECDSA", BouncyCastleProvider

I need a fixed length 64 Byte ECDSA signature with the NIST P-256 Curve. The implementation hast to use JCE. The following code sample can generate a signature and verify it. Provider provSign = new SunEC(); Provider provVerify = new SunEC(); // generate EC key KeyPairGenerator kg = KeyPairGenerator.getInstance("EC", provSign); ECGenParameterSpec ecParam = new ECGenParameterSpec("secp256r1"); kg.initialize(ecParam); KeyPair keyPair = kg.generateKeyPair(); PrivateKey privateKey = keyPair.getPrivate(); PublicKey publicKey = keyPair.getPublic(); try { // export public key KeyFactory kf =

I'm following Apple's guide towards composing a CloudKit Web Services request. The bit I'm having trouble with is Step 2, under "Authenticate Web Service Requests": Compute the ECDSA signature of this message with your private key. Before getting to this point, I generated my certificate, a .pem file, which when opening it in a text editor shows me my private key, so I have that in string format too. I've also followed the steps for generating what it refers to as a message, which I now have as a string. So given that I have a private key, (or the .pem file if required), and a message as a

i need to generate a ECDSA signature on C# side, and after reading and verify the signature on android application using (obviously) the relative public key. Well, to get a ECDSA key pair in java (with bouncy castle provider), the code is like that kpg = KeyPairGenerator.getInstance("ECDSA", "BC"); ecSpec = new ECGenParameterSpec("secp224k1"); kpg.initialize(ecSpec, new SecureRandom()); The string "secp224k1" , is the curve name. And i can choose "secp224k1","secp224r1","secp256k1","secp256r1" and more others. My questions is: Which is the equivalent curve name in C# mentioned above? Could

How to encode an ECDSA PublicKey on Java Card so that after I can decode it on another platform (e.g. sending the encoded key in a response APDU and processing it in a standard Java application)? keyPair.getPublic().getEncoded() on Java would do the trick with PKCS#8 encoding, but as far as I know getEncoded() is not available on the Java Card platform. You can implement this function like this: Card side: 1 KeyPair.getPublicKey() --> publicKey; 2 publicKey.getW() --> W; 3 Send W to outside; Standard java application side: 1 get W data bytes; 2 W data bytes --> ECPoint; 3 Build PublicKey with

Closed. This question is off-topic. It is not currently accepting answers. Learn more . Want to improve this question? Update the question so it's on-topic for Stack Overflow. To keen downvoters and/or closers: If you think this is offtopic for SO, kindly point me out other StackExchange site where this question would be more appropriate. How to implement ECDSA curve secp256k1 in PHP? Or rather: Are there any solutions - ie. includable specialized classes - already done? I can see there are plenty of opensource libraries, classes and stuff available for other languages (JavaScript, Python,...)