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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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ECDH Shared secret derived from OpenSSL and BouncyCastle are not always the same although constants and domain parameters are the same for both

I'm trying to implement AES cryptography between an iOS app and a java servlet. Java servlet uses BouncyCastle library while iOS app uses OpenSSL. Although I've used same public/private key pair and domain parameters for both side, shared secret…
anonim
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Java 7 keytool Elliptic Curve Encryption

I'm trying to create a keystore using keytool with a keyalg ECC. This should be possible according to Oracle. I quote: Area: Tools Synopsis: The keytool and jarsigner tools now support the ECC algorithm in keypair generation and jar signing. RFE:…
Bruno Lowagie
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How to calculate point addition using Jacobian coordinate-system over elliptic curves

I'm writing a small project of elliptic curve cryptography, and the program works well when I use affine coordinate system, which means each point is represented by 2 coordinates (x',y'). Now I'm trying to replace affine coordinate system by…
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Is it possible to use elliptic curve cryptography for encrypting data?

So far I have only seen it used in digital signatures and key agreement protocols. Can it be used like RSA to actually encrypt data? Are there any libraries for this? Edited: I need something like RSA. Encrypt the data with the recievers public key…
stribika
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EC private key recovery from PEM format with BouncyCastle

My application stores private keys in PEM format, the existing code works for RSA keys but I am trying to switch to EC keys and there is a problem. The key recovery seems to work, and the equals method on the recovered key returns true for the…
Bruce Skingle
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Good library for pairing based cryptography in Java

I am looking for a good library that can perform pairing based cryptography (PBC). One I could find is jPBC What have others used? and their experiences? The idea is to test the performance of algorithms using standard pairings (Weil, Tate) as well…
Jus12
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ES256 JWT validation - SignatureException: invalid encoding for signature: java.io.IOException: Sequence tag error

Hi I have a JWT which is signed using Elliptic Curve ES256 am trying to validate…
Hugh Pearse
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Encrypt AES secret key with Elliptic Curve ElGamal

There is Alice and Bob. I want to realize the following process: Alice encrypts a text with AES and generates a secret key Alice encrypts this secret key with Bobs public key using Elliptic Curves with El Gamal Alice sends the encrypted text &…
aslanj
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.NET Core 3 unable to load ECC private key

Thanks to Loading an ECC private key in .NET, I'm able to load ECC private keys into .NET Core 3 and performing signature tasks with them. I have, however run into one key that cannot be loaded by ECDSA.ImportPrivateKey. What's weird is that looking…
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Java - Create XML Digital Signature using ECDSA (Elliptic Curve)

We can create XML Digital Signature using RSA keys. But how do I use elliptic curve keys to sign xml files ? I get error messages such as - Exception in thread "main" java.security.KeyException: ECKeyValue not supported at…
user2531191
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How can you use .NET Core to support Safe Curves in ECC (eg. Curve25519)

It appears that .NET Core supports creation of custom curves in ECC. I've tried to define the Curve25519, as shown below: public class Curves { // TODO: check the key gen rand. public static ECCurve Curve25519 { get { …
Artem
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Number of points on elliptic curve

If you have an elliptic curve in the form of: y^2 = x^3 + a*x + b (mod p) Is there a good program to calculate the number of points on this curve? I have read about Schoof's and Schoof-Elkies-Atkin (SEA) algorithm, but I'm looking for open source…
Omega
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Elliptic curve point addition over a finite field in Python

In short, Im trying to add two points on an elliptic curve y^2 = x^3 + ax + b over a finite field Fp. I already have a working implementation over R, but do not know how to alter the general formulas Ive found in order for them to sustain addition…
Raylan
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Use ecc for encryption in ios

I am trying to implement ecc technique for encryption. I went through the following posts: Shared Secret based on Elliptic curve Diffie–Hellman with CommonCrypto Elliptic Curve Crypto in iOS which doesn't have any satisfactory solutions. Now, I…
SandeepAggarwal
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What makes the trapdoor function in elliptic curve cryptography hard to reverse?

I've been reading this article on elliptic-curve crypto and how it works: http://arstechnica.com/security/2013/10/a-relatively-easy-to-understand-primer-on-elliptic-curve-cryptography/ In the article, they state: It turns out that if you have two…
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