Proof of Work Reimagined: Why Argon2id Became Keycloak's Best Bot Defense

Traditional proof-of-work defenses fail against sophisticated attackers with GPU access, making rate limiting insufficient for protecting authentication endpoints. This Keycloak extension leverages Argon2id's memory-hard properties to shift computational bottlenecks from raw CPU speed to memory bandwidth, rendering GPU clusters economically unviable for credential stuffing attacks. The approach combines honeypot fields, timestamping, and adaptive difficulty to create multi-layered defense that protects legitimate users while making attacks prohibitively expensive.