Self-hosted anonymous survey infrastructure:
- LimeSurvey (self-hosted): Full-featured open-source survey platform. Disable IP logging in settings. Anonymize responses by default. Deploy on Iceland VPS for maximum legal protection of sensitive research data.
- Cryptpad Forms: Privacy-focused document and form platform. End-to-end encrypted by design. Can be self-hosted on bulletproof VPS.
- Custom form backend: Simple PHP or Node.js forms that write responses to database without storing IP address, user-agent, or timing correlation data. Maximal anonymity through minimal data collection.
For maximum respondent anonymity, combine with Tor .onion access to the survey URL. Respondents access survey through Tor, preventing network-level correlation of their identity with their survey response.