Summary: Scaling Ethereum & Multichain DeFi (Bancor x Polygon)

Hi fellow Bancorians! I’ve summarized a conversation on Twitter Spaces between Hamzah Khan of Polygon and Mark Richardson of Bancor. Hope it will be of use as a tl;dr and start discussion about the collaboration!

Link to the Bancor tweet here:

@_khanhamzah – Head of DeFi @0xPolygon
@MBRichardson87 – Product Architect and Head of Research @Bancor

Polygon as one of the first scaling solutions

  • Made scaling a possibility and accessible to all
  • Was at the center of both the DeFi craze → NFT and gaming craze

Polygon scaling products

  • Began with MATIC plasma chain in 2017 → POS chain mainnet launched in April 2020
  • Goal is adoption for millions, which cannot be done with just POS chain, and plasma chain has similar problems to optimistic rollups (more below)
  • ZK rollups from Starkware, Polygon Hermez and zkSync getting ready during this time, providing near “infinite scalability” and Ethereum-level security → Polygon saw ZK as the future

Should Bancor deploy on POS chain or Hermez?

  • POS chain has most traction with many blue-chip protocols (Aave, Balancer, Compound, Opensea)
  • For now, best to deploy on POS, then copy-paste / port onto Polygon Hermez (ZK EVM)
  • Hermez = ZK rollup of Ethereum running alongside POS chain, team is led by Jordi Baylina (1 of 2 people who saved ETH from theDAO hack)

Difference between scaling solutions

  1. Hermez: first decentralized ZK solution
  2. Miden: VM to be plugged into any ZK implementation
  3. Zero: focused on speed, uses Plonky2 (fastest ZK proof – 0.2s on MacBook Air)
  4. Nightfall: privacy-focused ZK solution
  • All of these solutions will be L2, which means same level of security as Ethereum

Clarifications to common misconceptions

  • With rollups, Ethereum will be different, faster, cheaper
    • L2s were advertised this way, but truth is these are chains work side by side and share the burden of Ethereum by dragging projects off the main chain
  • Polygon POS chain as a side chain
    • It is somewhat a hybrid between a side chain and L2 because MATIC staking and checkpointing is done on Ethereum, not Polygon POS chain

Competition in L2

  • Polygon has been in the space for longest and over time realized that optimistic rollups will not scale because of the 7-day withdrawal period (bad UX)
  • Optimistic rollups will still have their place in the near future - easy to port projects (ZK = scalability and the future, Optimistic = simplicity and short term)
  • Polygon is fully committed to Ethereum – Ethereum is where most, if not all, innovation is taking place, which is then copied to other chains


  • Polygon POS bridge – 3rd most used Ethereum app (after Opensea and Uniswap v2) and so far, no funds have been lost in past years
  • Works by consensus of 2/3 of 100 validators on Ethereum – which takes time, especially during Ethereum congestion
  • Alternatives are centralized bridges or relayers (at users’ discretion)


Regaining lost confidence for Polygon users

  • Bug bounties are in place to explore and expose exploits, securing the chain for the future
  • Technical and security team talent has been beefed up recently and will work hard to minimize these risks

ZK rollup timeframe

  • Still in early stage relative to optimistic rollups, but significant progress has been made with Hermez testnet launched next month

Difference to other ZK rollups

  • EVM compatibility (Starknet/Starkware and zkSync are centralized)
  • EVM was not made for ZK, so Hermez is built from the ground up as an entirely new EVM

Hi @bungeegum,

Thanks for this post. FYI, there is a discussion about deploying Bancor on Polygon happening here as well:

1 Like