jsrsasign
opensource free pure JavaScript cryptographic library supports RSA/RSAPSS/ECDSA/DSA signing/validation, ASN.1, PKCS#1/5/8 private/public key, X.509 certificate, CRL, OCSP, CMS SignedData, TimeStamp and CAdES and JSON Web Signature(JWS)/Token(JWT)/Key(JWK)
passport-jwt
Passport authentication strategy using JSON Web Tokens
maskdata
Node module to mask various kinds of data in the required formats