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3 articles with this tag.
OPAQUE is a password-authenticated key exchange that gives a server nothing to steal: not the password, not a dictionary-attackable verifier. Learn the oblivious pseudorandom function at its core, the envelope that hides a client's key pair, and the 3DH handshake, with Python code that reproduces the official RFC 9807 test vectors.
30 min read
ECDH lets two parties agree on a shared secret using points on an elliptic curve. Learn how P-256, P-384, and secp256k1 define the group, how public keys are encoded and validated, why the secret is only an x coordinate, and how an invalid-curve attack works.
23 min read
ECDSA is the elliptic curve version of DSA, used to sign TLS handshakes and Bitcoin transactions. Learn how signing and verifying work, why a repeated nonce reveals the private key, how RFC 6979 removes that risk, and how a signature is encoded.
23 min read
