- Bcrypt
- A password-hashing algorithm specifically designed to be slow, used by Supabase Auth to protect account passwords. Different from PBKDF2, but the same defensive principle: make each guess expensive.
- CAPTCHA
- Completely Automated Public Turing test to tell Computers and Humans Apart. The challenge that asks "are you a robot?". Holdfast uses Cloudflare Turnstile, a modern CAPTCHA that usually verifies invisibly without showing a puzzle.
- CDN (Content Delivery Network)
- A network of servers around the world that caches and serves static files (images, scripts) close to wherever the user happens to be.
- CORS (Cross-Origin Resource Sharing)
- A browser security mechanism that controls which websites are allowed to talk to which APIs. Holdfast's CORS policy restricts API access to its own domains, preventing other sites from impersonating users.
- CSP (Content Security Policy)
- A set of rules sent by Holdfast to your browser, telling it which scripts and resources are allowed to run on the page. Blocks classes of attack where an injected script tries to steal information.
- Credential stuffing
- An attack where lists of passwords leaked from other websites are tried automatically against your service, on the assumption that people reuse passwords. Defended against with CAPTCHAs, rate limits, and 2FA.
- HSTS (HTTP Strict Transport Security)
- A browser directive that forces all future connections to a site to use encrypted HTTPS, even if the user types a plain http:// address. Prevents a class of network attacks.
- HttpOnly / Secure / SameSite
- Cookie attributes that restrict how cookies behave. HttpOnly hides cookies from JavaScript (defending against script-injection theft); Secure restricts cookies to encrypted connections; SameSite stops cookies being sent on cross-site requests (defending against forged-request attacks).
- IDOR (Insecure Direct Object Reference)
- A category of bug where a user can access another user's data by guessing or modifying an identifier in the URL or request. Holdfast defends against this with two independent layers: application-level checks and database-level row-level security.
- Magic link
- A login mechanism where, instead of typing a password, you click a unique link sent to your email. Convenient, and as secure as your email account.
- MITM (Man-in-the-Middle)
- An attack where a third party secretly intercepts communication between two parties. In the context of Holdfast, the unavoidable theoretical risk is that a server operator could "man-in-the-middle" the JavaScript bundle delivered to your browser.
- OWASP Top 10
- The Open Worldwide Application Security Project's regularly updated list of the ten most common and serious web application vulnerability categories. The standard reference checklist for web security review.
- Pen test (penetration test)
- A controlled, authorised attempt by a security firm to break into a system, in order to find weaknesses before a real attacker does.
- Rate limiting
- Capping how many requests a single user or IP address can make in a given time, to prevent abuse such as automated guessing.
- Row-level security (RLS)
- A database feature where access rules are enforced inside the database itself, not just in the application. Holdfast uses Postgres RLS so that even if a bug in the application code forgot to filter by user, the database would still refuse to return another user's row.
- SOC report (SOC 2)
- Service Organization Control report — a third-party audit of a service provider's security practices. The "gold standard" formal assurance for enterprise buyers. Holdfast does not currently have one and does not claim to.
- Subresource integrity
- A browser feature where a webpage specifies the expected fingerprint of every script it loads. If the script has been tampered with, the browser refuses to run it.
- Supply chain (attack)
- An attack where a malicious party compromises a third-party component (an open-source library, a build tool, an analytics script) used by the target application, rather than attacking the target directly.
- Token / tokenised link
- A unique, single-use, time-limited string embedded in a URL. Holdfast's check-in emails contain tokenised links so that one click can mark you as "still alive" without requiring you to log in.
- TOTP (Time-based One-Time Password)
- The six-digit code that rotates every 30 seconds in apps like Google Authenticator or Authy. The standard form of two-factor authentication (2FA).
- Turnstile
- Cloudflare's CAPTCHA product, used by Holdfast on signup, account recovery, and the support form.
- Two-factor authentication (2FA)
- A login mechanism requiring two independent proofs of identity — typically something you know (password) plus something you have (a phone showing a TOTP code). Defends against stolen passwords.