Validator-nodes operator for public proof-of-stake and private blockchain networks. Intelligent protection against user account fraud and hijacks. Castle learns from users'​ behavior, and identifies suspicious activity in real-time. Castle tracks fraudsters based on device fingerprint, keystrokes, site browsing history, and hundreds of other signals. Administrators are alerted and high-risk accounts are automatically locked the second someone starts behaving suspiciously or tries to log in with a stolen password.