NB: Since the recording of this podcast LazyLedger changed their name to Celestia. Celestia is a scalable general-purpose data availability layer for decentralized apps and trust-minimized sidechains. It is a minimal, viable blockchain which does time stamping and block ordering. Think back to Bitcoin in the early days, before Ethereum. Layer-2 systems were being built on top of Bitcoin and were leveraging Bitcoin’s consensus layer. This is what Celestia is doing, although it is purpose built and scalable for the exact use case. The implementation details are a lot more complex, and the vision is to create a modular pluggable Layer-1 that does nothing but consensus and data availability. It is designed for people who want to create their blockchain without consensus. The project is yet to be launched, however we had Ismail Khoffi, Co-Founder and CTO, and Mustafa Al-Bassam, Co-Founder and CEO on the show to give us a deep technical overview and vision of Celestia. Topics covered in this episode: Ismail and Mustafa's backgrounds, and how they got into the crypto spaceHow Ismail and Mustafa met and created CelestiaThe Data Availability paper which was co-written with Vitalik and introduction to CelestiaThe purpose and function of CelestiaHow data availability works and the advantages and disadvantages to their ledgerThe purpose of CelestiaHow transaction fees workThe interoperability aspectHonest validators on the blockNon-interactive proofs on CelestiaThe interaction between Celestia and Cosmos SDKHow will Celestia compete with other Layer One's, in particular FilecoinWhen the ledger will be launchedEpisode links: Celestia websiteCelestia blogGitHubCelestia TwitterIsmail on TwitterMustafa on TwitterSponsors: Algorand: To learn more about Algorand and how it’s unique design makes it easy for developers to build sophisticated applications. - https://algorand.com/epicenterThis episode is hosted by Brian Fabian Crain & Sunny Aggarwal. Show notes and listening options: epicenter.tv/359

NuCypher is a decentralized threshold cryptography network offering interfaces and runtimes for secrets management and dynamic access control. It provides cryptographic infrastructure for privacy preserving applications and it exists as a smart contract on the Ethereum blockchain. They are currently in testnet but once launched you will be able to use NuCypher to carry out proxy re-encryption. Proxy re-encryption is a cryptographic method that allows you to delegate re-encryption of data to a third party and in this case validators in the NuCypher network. With this method you issue a re-encryption key that is assigned to a specific public key and a third party has the ability to re-encrypt data for that third party to decrypt. In this case the NuCypher network acts as the third party service. It is useful for when you want to share data, with the ability to revoke access at a later stage.  They also have an interesting token distribution mechanism called the WorkLock. This is similar to a Lockdrop but with work required from the participants. MacLane Wilkison, Co-founder and CEO of NuCypher talks about how and why the protocl was created, the challenges faced with it, and the problems it solves. Topics covered in this episode: - MacLane’s background and how he got into the blockchain space - Challenges with working with corporate entities and getting people to understand privacy preserving technologies - The zeroDB protocol and how that led to NuCypher - What was MacLane’s goal with starting NuCypher - What proxy re-encryption is and why it’s desirable over manual systems - What are threshold signatures - Attributability on the protocol - Some use cases of using FHE on NuCypher and why they have chosen this for the protocol - MacLane’s thoughts on trusted hardware - The infrastructure of NuCypher and why it is on Ethereum - Results from the testnet - WorkLock - their token distribution mechanism and how it compares to Lockdrop - How you can set up a node on NuCypher - Current gas costs and the impact of this - The NuCypher business model and how they make money - Where to learn more about NuCypher Episode links:  - [NuCypher Website](nucypher.com) - [NuCypher Discord](https://discord.com/invite/7rmXa3S) - [NuCypher blog](https://blog.nucypher.com/) - [WorkLock](https://blog.nucypher.com/the-worklock/) - [NuCypher Twitter](https://twitter.com/NuCypher) - [MacLane's Twitter](https://twitter.com/MacLaneWilkison) Show notes and listening options: [epicenter.tv/357](https://epicenter.tv/357)