Bitcoin Security for Proof of Stake? Why Not, Says Babylon

Babylon, a crypto security blockchain using Bitcoin’s proof-of-work security to integrate with proof-of-stake chains, plans to expand beyond the Cosmos.

Designed by David Tse and his team at Stanford’s Blockchain Consensus Protocol Lab, Babylon was created using the Cosmos Software Development Kit (SDK). It communicates with Bitcoin through a Bitcoin timestamping protocol.

This means that it interacts with the Bitcoin chain by sending events on Babylon onto the Bitcoin chain, Tse told Blockworks in an interview.

In Satoshi Nakamoto’s original Bitcoin white paper, the author noted how they wanted to build Bitcoin to become a timestamping server, Tse said.

“In his case, he was interested in timestamping Bitcoin transactions,” Tse said. “It turns out that you can also put arbitrary data onto the Bitcoin chain, so this allows you to timestamp not only Bitcoin transactions but also events happening outside of the Bitcoin chain.”

Using this knowledge, Babylon is able to timestamp events occurring on different proof-of-stake chains.

Wait, so how does it make the blockchain more secure?

Existing proof-of-stake chains such as Osmosis already have a handful of validators signing off on transactions.

What Babylon does through Bitcoin timestamps is bring in a second-level committee to certify the transaction.

“For smaller transactions of $1,000 or a few hundred, the proof-of-stake committee is enough — they’re fast to validate and approve transactions, but if you have a transaction that has very high value or transactions that actually affect the security of the proof-of-stake chain, that will deserve an extra level of protection from Bitcoin,” Tse said.

An example Tse notes would be unbinding transactions, where the transaction itself will affect the security of the validators. “Bitcoin is slower, but it has a much higher level of security,” he said

Babylon is currently integrated with 16 different app chains on their testnets that have a value of $1.4 billion. These 16 different app chains are secured using Bitcoin’s $600 billion.

Beyond the Cosmos

Babylon currently exists as a testnet and plans to launch its mainnet in Q3 or A4, Tse said.

The Cosmos ecosystem has been its focus for a handful of reasons — notably its powerful interoperability capabilities through its inter-blockchain communication protocol (IBC) which enables automatic time stamping from all these chains to Babylon, but also due to its diverse app chain ecosystem.

“This gives us very broad exposure to different kinds of applications…We learn quite a bit working with them and understanding how they want to use Bitcoin security,” Tse said.

Although this is the case, Babylon is also looking at ways it can expand beyond the Cosmos. This is currently being explored in two different directions, one of which is implementing smart contracts on Babylon that create timestamping.

“This allows us to go outside the Cosmos ecosystem…it doesn’t even have to be chains, it could be specific applications that are running on Ethereum that want additional security,” Tse said. “Bitcoin is very powerful, very secure, but it has a very big limitation…which is it doesn’t have smart contracts, so Babylon deals with the difficult work of interacting with the not-so-smart chain Bitcoin and enables it to interact with the rest of the world.”

The second direction, Tse notes, is to integrate with interoperable chains — such as Axelar.

“Axelar is interoperable with many chains outside the Cosmos, then we can get timestamps for all these chains Axelar is integrated with as well,” he said.

Using Bitcoin security to build dapp projects

Instead of competing directly with Ethereum, Tse believes it is possible to bring existing proof-of-stake chains to an even more secure Bitcoin through interoperability.

“Ethereum has been very successful in building an ecosystem that incorporates brilliant new technology,” Tse said. “So what we’re saying here is that Bitcoin is an arguably even more secure chain and it has a 14-year history.”

Babylon is not the only project that Tse and his team are working on.

Using ordinal technology, Tse and his team are currently looking into ways to use Bitcoin block space to eliminate censorship of transactions on proof-of-stake chains.

“You could put these transactions onto the Bitcoin block space and because Bitcoin has [a] very strong censorship resistance property, that would allow that transaction to survive the censorship… that is another type of protocol that is on our roadmap,” Tse said.

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