Curve X448 is one of the most widely used ECC methods and is defined in [RFC 7748]. This page will take the two vectors defined in the RFC, and check the output. [secp256k1 barebones][P256 barebones][P521 barebones][Curve 25519 barebones]. With X448, we have an input u-coordinate value (the x-value) and a scalar value, and we get an output u-coordinate. The vectors are:
Alice's private key, a: 9a8f4925d1519f5775cf46b04b5800d4ee9ee8bae8bc5565d498c28d d9c9baf574a9419744897391006382a6f127ab1d9ac2d8c0a598726b Alice's public key, X448(a, 5): 9b08f7cc31b7e3e67d22d5aea121074a273bd2b83de09c63faa73d2c 22c5d9bbc836647241d953d40c5b12da88120d53177f80e532c41fa0 Bob's private key, b: 1c306a7ac2a0e2e0990b294470cba339e6453772b075811d8fad0d1d 6927c120bb5ee8972b0d3e21374c9c921b09d1b0366f10b65173992d Bob's public key, X448(b, 5): 3eb7a829b0cd20f5bcfc0b599b6feccf6da4627107bdb0d4f345b430 27d8b972fc3e34fb4232a13ca706dcb57aec3dae07bdc1c67bf33609 Their shared secret, K: 07fff4181ac6cc95ec1c16a94a0f74d12da232ce40a77552281d282b b60c0b56fd2464c335543936521c24403085d59a449a5037514a879d