Every document sealed on PaySeal uses production-grade algorithms from Node.js's built-in crypto module.
// SHA-256 hash of your document
const hash = crypto.createHash('sha256').update(fileBuffer).digest('hex')
// Ed25519 digital signature
const sig = crypto.sign(null, Buffer.from(hash), privateKey)
// Verification
const valid = crypto.verify(null, Buffer.from(hash), publicKey, sig)