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Questions tagged [elliptic-curve]

In mathematics, an elliptic curve is a smooth, projective algebraic curve of genus one, on which there is a specified point O.

In mathematics, an elliptic curve is a smooth, projective algebraic curve of genus one, on which there is a specified point O (the point at infinity). An elliptic curve is in fact an abelian variety — that is, it is a (necessarily commutative) group with respect to an algebraically defined multiplication — and O serves as the identity element. Often the curve itself, without O specified, is called an elliptic curve.

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Elliptic Curve Base Point Scalar Mulitplication JPair Library

I have to multiply two field elements (f1 and f2) with the base point P on the elliptic curve defined using the Weierstrass equation i.e. y2 = x3 +ax +b. I know in scalar multiplication, the point is added those many numbers of times to get the…
Aisha
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How to troubleshoot OpenSSL BN_bin2bn() causing segmentation fault?

Calling the following method produces a segmentation fault on the BN_bin2bn call: #include #define ECIES_PUBLIC_KEY_SIZE 32 static int doBin2Bn(const uint8_t* someValue) { BIGNUM *bn = NULL; bn = BN_new(); …
Brandon
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How to change the key length of ECDSA?

Recently, I was trying to do something with the code of ECDSA. I want to change the key length of it but in vain. I checked the internet and found some source code of ECDSA, but somehow it only allows 32 bytes. For example, I found…
YMbrothers
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Elliptic Curve PublicKey sharing between different platforms

I am trying to communicate between android(client), ios(client) and .net(webapi) platforms with Elliptic Curve. When I try to generate public key on android platform with SpongyCastle, my web api could use this public key. This key's bytes length is…
oyenigun
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How to generate EC keypair with Bouncy Castle

my current project is using the fips resources of BouncyCastle only for encrypten/decryption signing and so on.. the keys are still generated with the usual C# bouncy castle. Now, because that is a waste i want to change the code, but i can't find…
Alex R.
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Why does public key blob contains key type and key length in big endian format in .net framework 4.7?

I wrote following code to extract ECDH public key blob: var curve = ECCurve.NamedCurves.nistP256; ECDiffieHellman ecdh = ECDiffieHellman.Create(curve); var bytes = ecdh.PublicKey.ToByteArray(); …
Raghu
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How to properly prepare for ECC encryption using .net framework 4.7?

In ECC encryption process, I (as a sender) am assuming that I would do following: Use an elliptical curve (identified as say, NIST P-256) to generate ephemeral (temporary) public and private key pair Get hold of public key of the receiver (i.e. the…
Raghu
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EdDSAPublicKey Serialization Java

Is there a way to serialize EdDSAPublicKey in java. There a method getEncoded() in EdDSAPublicKey but how to get back a EdDSAPublicKey from the encoding.
Subhankar
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How to compute polynomials in CPABE Scheme based on Elliptic Curves?

I am implementing the CPABE scheme proposed in paper CPABE based on Elliptic Curves using Charm Crypto Library Charm. I have written the setup function correctly but I am having a problem in KeyGen, Encrytp and Decrypt functions where different…
Aisha
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Can I create a JCE ECPublicKey from a Q value from an openssh public key and ECParameterSpec

I'm reading openssh format elliptic curve public keys (RFC 5656, section 3.1) and would like to get from a BigInteger Q value to an ECPublicKey instance using JCE (rather than say BouncyCastle). I want to do this to verify JWT signatures. e.g.…
David Carboni
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How to get Qx and Qy form DER Encoded EC_POINT

I created a brainpool EC on a nitro key hsm and want to use this for crypto operations with the .NET Framework e.g. System.Security.Cryptography.ECDiffieHellman. I extracted with pkcs11-tool --list-objects the public key but get only one value, the…
hdev
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Compiling through gcc and using -ltr results in an error, how to fix it?

Iwant compile the fourQ lib from Microsoft foe ARM-architecture. When I try to link the parts it turns me out an error: FourQ_x64_and_portable>make CC=gcc ARCH=ARM GENERIC=TRUE gcc -c -O3 -D _ARM_ -D __LINUX__ -D _GENERIC_ …
Shalec
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How to run the FourQ lib by Microsoft at 32-Bit?

I figured out how to run FourQ at 64-Bit, but now I want to run it through 32-Bit architecture. First of all the lib can be found at [1]. I'm running the stuff from "FourQ_x64_and_portable" directory. If I try the command, as suggested in the…
Shalec
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Elliptic Curve Cryptography PHP: catchable fatal error argument 1 passed to __construct()

I am trying to use Elliptic Curve Cryptography using Matyas Danter's phpecc libraries available in 1 . However, I am getting the following error when I create the variable Alice , although the passed argument is a Point.. please help.. Catchable…
Haya Raed
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Get key parameters from imported Elliptic Curve key in ASN.1 format

I need to write code that gets as input Elliptic Curve key in ASN.1 format. The input byte array is…
Dropper
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