Those who have been in crypto long enough remember the not-so-good-ol’ days when an air-gapped machine was the only way to store private keys securely. Thankfully, the wallet space has come a long way from that era. But we still live in a world where the seed phrase is the single atomic point of failure. Enter threshold signatures schemes (TSS), a multi-party computation (MPC) where different parties generate a key and are all required to create a valid signature. 

We’re joined by Omer Shlomovits and Ouriel Ohayon, Co-founders of ZenGo. Their product is a ‘keyless’ crypto wallet, which means users never need to generate or store a key which gives them access to their funds. Keys are created with an MPC, where both ZenGo and the user are required to sign a transaction. TTS opens up exciting new possibilities like social recovery, user permissions for teams, and inheritance planning schemes. The important distinction between ZenGo and existing multi-signature wallets is that they achieve this using only cryptography, and do not rely on on-chain elements like smart contracts or op_scriptSig in Bitcoin.

Topics covered in this episode:

- Omer and Ouriel’s respective backgrounds in academia and online consumer-facing products
- What lead them to want to build yet another crypto wallet
- The state of custody in the crypto wallet ecosystem and the challenge which remain unaddressed
- A quick refresh on cryptographic primitives and multi-party computations (MPC)
- The building blocks of cryptographic signatures and threshold signature schemes (TSS)
- How TSS is different from Bitcoin multi-sig and smart contract multi-sig
- TSS in ECDSA vs. Schnorr signatures
- Applications and use cases for TSS
- ZenGo’s on-boarding, restore process and use of biometrics
- The future of wallet interoperability in a world of proprietary cryptographic schemes

Episode links: 

- [ZenGo: Bitcoin & Cryptocurrency Wallet](https://zengo.com)
- [‎ZenGo: Bitcoin & Crypto Wallet on the App Store](https://Zengo.com/enjoy)
- [Threshold Signatures Explained](https://www.binance.vision/security/threshold-signatures-explained)
- [ShareLock: Mixing for Cryptocurrencies from Multiparty ECDSA](https://eprint.iacr.org/2019/563.pdf)
- [KZen Networks on GitHub](https://github.com/KZen-networks)
- [Zengo Research](https://zengo.com/research/)
- [KZen Research Telegram Group](https://t.me/kzen_research)
- [Tel Aviv Blockchain Week Recap with Anna Rose of the Zero Knowledge Podcast](https://www.youtube.com/watch?v=ccywXWTSFKM)

Sponsors: 
- Vaultoro: Trade gold to Bitcoin instantly and securely starting at just 1mg - http://vaultoro.com
- Trail of Bits: Trust the team at the forefront of blockchain security research - https://trailofbits.com

This episode is hosted by Sebastien Couture & Brian Fabian Crain. Show notes and listening options: [epicenter.tv/306](https://epicenter.tv/306)