Payy and Payy Card, the Undoxable Credit Card

In this episode, Anna Rose (x.com/annarrose) and Tarun Chitra (x.com/tarunchitra) catch up with Sid Gandhi (x.com/sidgandhi_xyz) and Calum Moore (x.com/calummoore) from Payy (x.com/payy_link) to discuss the Payy private payment system and the newly released Payy credit card. They explore their focus on building a user-friendly privacy focused product, how ZK tooling advancement makes this possible, and a walkthrough into how it works with the Visa remittance system. Sid and Cal explain Payy's design as a ZK Validium rollup on Polygon, using client-side proofs and a Merkle tree to ensure privacy and compliance.

The discussion also delves into the history and past challenges of self-sovereign payments; how self-sovereign money goals were overshadowed by speculation, why many new stablecoin projects feel like a step back to traditional finance, and how privacy-focused payments are making a comeback in 2025.

Related Links
• Payy Network (payy.network)
• Payy Wallet (payy.link)
• Payy Card (docs.payy.network/product/payy-card)
• Zcash (z.cash)
• The whitepaper for Payy Network (docs.payy.network/payy-network/whitepaper)
• The payy card launch on X (x.com/payy_link/status/1953093856326762639)
• Payy runner (runner.payy.link), anew way to earn payy points (x.com/payy_link/status/1966531809715638325)

ZK Whiteboard Sessions is an educational video series produced by ZK Hack. It is focused on the building blocks of zero knowledge technology. Find season 3 of the Whiteboard Sessions as well as previous seasons here (zkhack.dev/whiteboard/#season3).

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Read transcript (github.com/ZeroKnowledgefm/episode-transcripts…)