Election staff worry about instruction-override attempts reaching the elections FAQ model. Which gateway control best addresses that threat?

Instruction-override and prompt-injection attempts should be stopped at the AI gateway before they reach sensitive municipal models. Deploying a prompt firewall that strips or blocks override patterns protects an elections FAQ model from instructions that try to change system behavior, reveal hidden prompts, or produce unauthorized guidance about voting processes. Gateway enforcement scales across clients, complements model-side refusals, and creates a control point elections staff can monitor during high-risk periods when adversaries are more likely to probe civic information systems. Enforcing per-client rate limiting at the AI gateway to contain instruction-override attempts during traffic bursts only controls volume, but it does not inspect or strip instruction-override language, so malicious prompts can still reach the elections FAQ model even in a single low-rate request. Requiring mutual TLS authentication at the AI gateway to block instruction-override attempts from external clients verifies approved client certificates, but it authenticates the caller rather than scanning the prompt, so an authorized client can still send instruction-overrides to the model. Applying output toxicity screening at the AI gateway to filter instruction-override attempts in generated answers examines what the model produces rather than stopping override instructions before they arrive, so it does not prevent the override from reaching the elections FAQ model and it misses overrides that are not toxic. Exam caveat: prompt firewalls at the AI gateway are the primary preventive control against instruction override reaching elections models. Operational check: enable prompt-firewall rules for override phrases and role-hijack patterns, alert on blocks, retain logs for election-security review, and retest controls before major election events.