Public transaction history in blockchains represents one of their key features which, alongside immutability, aim to provide an alternative to CeFi. However, this transparency comes at a price: privacy. As a result, different solutions have been proposed, that preserve privacy while maintaining all the other benefits of blockchain technology, but there currently isn't a one-size-fits-all answer to this problem. For example, zero knowledge proofs convey the validity of a transaction batch without sharing any other details, but the underlying arithmetic circuits are both complex as well as computational intensive. Umbra proposes a system that relies completely on elliptic curve cryptography, employing multiple private-public key pairs to achieve stealth payments.We were joined by Ben DiFrancesco, founder & CEO of ScopeLift, to talk about Umbra's privacy preserving stealth token transfer system and if the need for privacy on blockchains outweighs any implicit UX frictions.Topics covered in this episode:Ben’s backgroundUmbra's missionHow Umbra worksNon-interactive key distributionPotential solutions (& trade-offs) for Umbra's computational intensityGenerating private-public key pairs by the Umbra smart contractUser experience (UX) for senders and receiversFee structure for deterring griefing attacksHow Umbra works for ERC20 tokens & NFTsPrivacy preserving withdrawals from stealth addressesPrivacy vs. UX frictionSmart wallets & account abstractionPrioritising privacyEpisode links: Ben DiFrancesco on TwitterUmbra on TwitterScopeLift on TwitterThis episode is hosted by Friederike Ernst. Show notes and listening options: epicenter.tv/496