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Questions tagged [ecdh]

136 questions
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Rust ECDH does not produce the same shared secret as NodeJS/Javascript and C implementations

I have ECDH shared secrets (sec1 and sec2, below) working in NodeJS/Javascript: let sk1 = crypto.createECDH('secp256k1') sk1.setPrivateKey(Buffer.from("71179b991d7693de813aeaa5bfa241a2ac9e0535867ebf8f6b1b0884472ef4a7", "hex")); let pk1 =…
fadedbee
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ECDSA KeyPair to Perform ECDH Shared Secret Encryption

I needed to be able to take an ECDSA keypair (private and public key) to then perform an ECDH to get a shared secret between two parties. In this case we are talking about Alice and Bob. I could not find any relevant C# examples anywhere and where…
mathis1337
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How to convert ECDH keys to PEM format with NodeJS crypto module

I want to have only one pair of keys that I can use for ECDH functions and for other function in node:crypto module. I know there are two ways how to generate keys with node:crypto module. One way is to use crypto.generateKeyPairSync. This generates…
David Novák
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(C#) Calculate key share using private key and public key on (EC)DHE x25519

I am working with (EC)DHE encryption type x25519 and I have a big problem on calculating shared key. I have three key: Alice’s private key: a : "984a382e1e48d2a522a0e81b92fd13517e904316c6687a59d66cd2e5d9519a53" Alice’s public key: Q(a) = a*G(a) :…
Kom Pe
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Is it necessary to have two coordinates for the public key of ECDSA?

I am trying to generate an ECDSA key-pair using an external library called easy-ecc. The thing that I do not understand is this library generates a single coordinate for public key. As far as I see from books, online ECDSA generators or NIST test…
Terminou
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ECDH for P-521 (Web Crypto Api) / secp521r1 (NodeJS Crypto) generate a slightly different shared secret

I have generated a public and private key pair with ECDH from NodeJS function _genPrivateKey(curveName = "secp384r1", encoding = "hex") { const private_0 = crypto.createECDH(curveName); private_0.generateKeys(); return…
jay
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Create secKey form data/hex/bytes using SecKeyCreateWithData give nil

I'm new to encryption. i want to create public seckey from data but i always get nil. Please help me. I need this public key as seckey to create a shared secrete key but i always get nil . how i can convert data to seckey? Below are the code for…
Sourav Mishra
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How Create 64 byte public and 32 byte private key Using ECDH encryption swift?

I have to protect my lock from MITM (i.e man in the middle attack). For that i have to integrate ECDH encryption. I have no knowledge related to this. Please help me how do i create 64 bytes public and 32 byte private key. below are the code i'm…
Sourav Mishra
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Elliptic Curve Diffie Hellman public key size

I want to use Diffie hellman for generating a secret key between a c# Server and c++ Client. this code generates a public key for the server: serverECDH = new ECDiffieHellmanCng(ECCurve.NamedCurves.nistP256); …
fjahan
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Encryption in swift using Diffie Hellman key exchange and an elliptic curve encryption

I've been trying to encrypt and decrypt a string in swift using a Diffie Hellman key exchange and an elliptic curve encryption. Following is the code that I followed. SWIFT Code : let attributes: [String: Any] = [kSecAttrKeySizeInBits as String:…
user7413163
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NIST p256 Point Decompression: Finding Y-Coordinate For Base Point

I'm trying to implement NIST P256 point compression and decompression and I keep getting the wrong y coordinate when I solve y = sqrt(x^3 + ax + b). I figured a good test of the decompression would be to take the base point G defined by…
TheSocraticParadox
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Implementing ECDH engine in OpenSSL 1.1.1

I am trying to write an OpenSSL Engine with ECDH support. I am following this page on the OpenSSL wiki : https://wiki.openssl.org/index.php/Creating_an_OpenSSL_Engine_to_use_indigenous_ECDH_ECDSA_and_HASH_Algorithms. However it is based on version…
runnenolleb
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how to convert a String to an ECDH PublicKey and check its connectness

I'm using Java with Bouncy Castle to convert a server-side string_1 to ECDH PublicKey, then convert the PublicKey to string_2 to check the code's correctness, but string_1 and string_2 are different and I don't know where's wrong. String key…
fanreson
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Protection of an ECC Key in an Android Application

I have done an Android Application using an ECC Key pair. When I have developed it last year, I wanted to create the ECC key in the Android Keystore. Unfortunately, this ECC key is used to generate a session key thanks to ECDH, and ECDH is not…
OlivierGrenoble
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openssl 1.0.2j, how to force server to choose ECDH* ciphers

I have client server which uses opensl 1.0.2j, and using RSA:4096 key and certificate and want to force the server to use only the following…
Naga
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