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BOB

Status
Mainnet
Type
Ethereum Rollup
Fee Token
ETH
TVL
â‚ż 974
BOB is an optimistic rollup that serves as an application layer for Bitcoin. They have launched as a rollup on top of Ethereum, with plans to derive more security from Bitcoin miners, and full nodes, over time. Its relation to Bitcoin, currently, is similar to that of a sidechain as it is an alternative consensus protocol with a two-way peg(s) between it and the Bitcoin mainchain.
CUSTODY
DATA AVAILABILITY
OPERATORS
FINALITY ASSURANCE

Layer Metrics

BTC Locked
Total amount of locked on per day
Trust Assumption Review
BTC Custody
Very High
🛑
Bitcoin users trust that bitcoin synthetics will remain backed, and that the BOB bridge will not steal their funds
tBTC and wBTC are minted on BOB via its official Ethereum bridge.

Users trust that the bridge operators will not steal their BTC, the BOB proposer to not publish a malicious, unchallenged state transition, or the admin controlling the bridge to create a malicious smart contract upgrade.

In the event of a malicious smart contract upgrade, there is no exit window for BOB users. This means that the admin behind the bridge can steal all funds in the official bridge.

🔬We are currently reviewing other bitcoin synthetics minted on BOB.
Data Availability
Medium
⚠️
Data is stored and made available by Ethereum full nodes
The data for BOB’s state is stored on the Ethereum blockchain. Anyone can run an Ethereum node and verify the state of BOB.
Network Operators
High
🚨
BOB blocks are produced and proposed by a centralized operator, but forced inclusion to Ethereum L1 possible
Currently, BOB’s sequencer is managed by one entity. The BOB sequencer can censor transactions and would also cause liveness failures if it went down. Users can bypass the sequencer and send their transactions directly to the Ethereum L1. Users do, however, trust that a permissioned proposer will publish the latest state root on the Ethereum L1, permitting withdrawals.
Finality Guarantees
Medium
⚠️
BOB state transitions finalize on Ethereum
BOB inherits finality guarantees from Ethereum. The BOB sequencer provides a soft confirmation of transactions which are eventually summarized and sent to Ethereum.

⚠️BOB's sequencer can reorg prior to a transaction batch being accepted on Ethereum.
Bitcoin Security
BOB does not inherit any security from Bitcoin
In its current state, BOB does not inherit security from Bitcoin.
ETH token used to pay fees
BOB users pay sequencer fees in ETH. BOB operators also pay DA fees in ETH.
No MEV introduced to Bitcoin
BOB does not introduce any MEV on the Bitcoin L1. Users trust the BOB sequencer to not reorder their transactions to extract MEV.
BOB does not contribute to the security budget
BOB does not currently contribute to the Bitcoin security budget.
Withdrawals
Proposer role centralized and permissioned. BTC users must withdraw to Ethereum L1 before withdrawing to Bitcoin
Users can bypass the sequencer and submit withdrawal requests directly to the Ethereum L1. However, they cannot force-exit as the self-proposing is not enabled. Users rely on the proposer to post updated state roots to Ethereum to ensure withdrawals can be processed. Withdrawals from BOB's official bridge to Ethereum take 7 days to finalize.

Once on the Ethereum L1, users can then redeem their BTC on Bitcoin via the two-way peg mechanism that their BTC synthetic is supported by.

Users primarily trust bridge operators to permit withdrawals back to the Bitcoin mainchain.
Technology
Ethereum Virtual Machine
BOB uses an EVM-compatible virtual machine. The Ethereum Virtual Machine is software responsible for smart contract execution for a number of blockchains, namely the Ethereum Network. It uses Solidity/Vyper as its code and is the dominant environment for smart contract execution in the cryptocurrency ecosystem. BOB is EVM-compatible, which means that a developer from Ethereum would have less difficulty deploying their applications on BOB compared to other execution environments.
Use Cases
Onchain applications
Onchain applications are supported. Onchain applications including borrowing and lending protocols, onchain exchanges (commonly referred to as decentralized exchanges), and more. These applications are supported with more expressive smart contract environments.
Source Code
Under review
We are reviewing if BOB's node software is open-source.
Knowledge Bits
Learn more