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Tools
ECDSA Signature Verifier
Verify any ECDSA signature
JWT ES256 Debugger
Decode & verify ES256/ES384/ES512 tokens
DER ⇄ Raw Converter
Convert signature formats
X.509 Certificate Decoder
Inspect certificates
Signature Error Explainer
Diagnose why verification fails
Nonce Reuse Checker
Scan a Bitcoin address for repeated r values
Test Vector Generator
Generate keys & signatures for your tests
SSH Key Inspector
Decode authorized_keys entries
Library Interop Cheatsheet
Why library A's signature fails in library B
OpenSSL Command Builder
Build the openssl command you need
JWKS & OIDC Checker
Check the key set behind your tokens
WebAuthn / Passkey Inspector
Decode passkey registration & login
Elliptic Curve Playground
See the math behind the signatures
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