> ## Documentation Index > Fetch the complete documentation index at: https://harbinger.mintlify.site/llms.txt > Use this file to discover all available pages before exploring further. # Welcome to Analog Labs > Analog Labs builds low-tech security tools. Our Human Verification Card helps you confirm you're talking to the right person when something feels suspicious. Mockup Of Two Piles Of Disorganized Business Cards 1550 El(1) Pn ## What is the Human Verification Card? The Human Verification Card is a small physical card covered with scratch‑off stickers. Under each sticker is a code that only you and your trusted contacts know. When you need to confirm a caller's identity, scratch a random circle and ask them to reveal the same code on their copy of the card. ## Why it Matters Phone and online scams often rely on quickly gaining your trust. By forcing an attacker to supply a secret code they shouldn't know, the card provides a simple second factor that anyone can use—no apps or passwords required. ## Next Steps Learn how to set up your cards Questions or feedback? Get in touch.