TransferFAQProtocols
FREQUENTLY
ASKED QUESTIONS
01 Omnichain Bitcoin
02 What is BTC.b?
03 The Omnichain Fungible Token Standard (OFT)
04 OFT Functionality
05 OFT Advantages
06 Bridge Functionality
07 Transferring BTC.b to Non-EVM Chains (Ex. Aptos)
08 How to acquire BTC.b
01
Omnichain Bitcoin
As the original crypto asset, Bitcoin forms the foundation of countless decentralized applications today. A wide variety of methods are currently used to transfer BTC across chains. Most of these methods rely on insecure middlechain architecture or trusted and centralized validator sets. Furthermore, there is currently no universal Bitcoin or Wrapped Bitcoin on all chains. Each chain has a different implementation of BTC that is not interoperable with others. With BTC.b and the OFT standard, users can now securely transfer their BTC across chains without facing these compatibility challenges.
02
What is BTC.b?
BTC.b is a newly launched wrapped version of Bitcoin on the Avalanche Network. BTC is moved to Avalanche via the Avalanche Bridge. BTC.b is an ideal candidate to bring true omnichain Bitcoin to all LayerZero supported chains.
03
The Omnichain Fungible Token Standard (OFT)
The OFT standard allows for any fungible token to be securely transferred across chains without the need for middlechains or trusted validators. The OFT standard is built on top of LayerZero’s innovative omnichain messaging infrastructure and is not subject to the security vulnerabilities of existing bridging solutions.
04
OFT Functionality
OFTs use LayerZero’s generic messaging primitive to allow applications deployed on multiple chains to transfer token balances to one another. This means that any fungible token can become an OFT and avoid the need to build for multiple conflicting blockchain standards. OFTs are instantly unified across all chains they are deployed on.
05
OFT Advantages
OFTs have major advantages over existing solutions built across multiple blockchain standards, including:



  • Security: Generic cross-chain messaging is a major improvement in overall security compared to existing middlechain and wrapped asset bridge solutions; transferred tokens are being issued by 1st party contracts on destination chains vs. 3rd party contracts with vulnerable wrapped assets.



  • Standardization: Token balances can move across chains and remain in their native form without the need to develop for countless standards (ex. ERC20, BEP20, SPL20).



  • Efficiency: All OFTs exist as native tokens and are completely free to use with the exception of gas costs. No bridging fees and efficient arbitrage across chains make OFTs the clear choice for omnichain tokens.



  • Unified Liquidity: Balances of OFT tokens can be modified seamlessly across chains resulting in truly unified liquidity without the fragmentation of existing solutions.



  • Composability: The OFT standard allows other decentralized applications to quickly integrate with omnichain tokens; all interactions and calls are easily accessible so long as an application has the token address (ex. Rapid integration with AMMs and exchanges).
06
Bridge Functionality
The BTC.b bridge allows users to securely transfer omnichain Bitcoin between Ethereum, BSC, Arbitrum, Optimism, Fantom, Avalanche, and Aptos. Users can securely transfer omnichain BTC.b tokens between chains using LayerZero’s messaging protocol and the OFT Standard. Remember, transferring BTC.b to non-EVM chains such as Aptos for the first time requires additional steps which are detailed below.
07
Transferring BTC.b to Non-EVM Chains (Ex. Aptos)
Registering & Claiming Assets
When sending BTC.b from a non-Aptos wallet to a destination Aptos wallet, users will be required to register and/or claim their BTC on Aptos. This is a result of the fundamental design differences between Aptos and other blockchains that are designed to enhance security.
Transferring Assets to Aptos for the First Time
Transferring BTC.b to Aptos wallets requires registration and claim transactions. This is done to enhance user security and is unique to Aptos.



Scenario 1: Users have gas assets available on the destination Aptos Wallet In this scenario, users transferring assets will be prompted to register their BTC.b on their Aptos wallet if it has not already been registered. Users will not be required to submit an additional claim transaction in this scenario.



Scenario 2: Users do not have gas assets available on the destination Aptos Wallet If a user does not have gas assets available on their destination wallet they will only have to claim their BTC.b once the transaction is finished. Users will receive APT tokens (for gas fees) on the destination wallet to pay for the cost of claiming their assets. This APT is paid for by the user on the source wallet and is transferred through to the destination.



Remember, these registration and claim requirements only apply when a user interacts with a token for the first time. Follow up transfers of the same token will not require these transactions.
Transferring Assets from Aptos to Other Chains
Transferring BTC.b from Aptos back to other chains (ex. Ethereum) does not require additional registration or claim transactions. Transfers out of Aptos are subject to a 2 to 3 day waiting period before the transaction is completed. This waiting period is for security purposes and allows for a significant number of blocks to be finalized before relaying messages to non-Aptos chains.
08
How to acquire BTC.b
  1. Buy BTC / Own BTC
  2. Download Core browser extension / Use Core web
  3. Transfer BTC to Core BTC addresses
  4. Bridge BTC using Core and receive BTC.b on EVM C-Chain address
  5. Connect Core to dApp with BTC.b / Transfer to chain of choice via https://bitcoinbridge.network/
  6. Use BTC.b as liquidity, in a vault, for trade, etc.
FREQUENTLY ASKED QUESTIONS
01 Omnichain Bitcoin
02 What is BTC.b?
03 The Omnichain Fungible Token Standard (OFT)
04 OFT Functionality
05 OFT Advantages
06 Bridge Functionality
07 Transferring BTC.b to Non-EVM Chains (Ex. Aptos)
08 How to acquire BTC.b
01
Omnichain Bitcoin
As the original crypto asset, Bitcoin forms the foundation of countless decentralized applications today. A wide variety of methods are currently used to transfer BTC across chains. Most of these methods rely on insecure middlechain architecture or trusted and centralized validator sets. Furthermore, there is currently no universal Bitcoin or Wrapped Bitcoin on all chains. Each chain has a different implementation of BTC that is not interoperable with others. With BTC.b and the OFT standard, users can now securely transfer their BTC across chains without facing these compatibility challenges.
02
What is BTC.b?
BTC.b is a newly launched wrapped version of Bitcoin on the Avalanche Network. BTC is moved to Avalanche via the Avalanche Bridge. BTC.b is an ideal candidate to bring true omnichain Bitcoin to all LayerZero supported chains.
03
The Omnichain Fungible Token Standard (OFT)
The OFT standard allows for any fungible token to be securely transferred across chains without the need for middlechains or trusted validators. The OFT standard is built on top of LayerZero’s innovative omnichain messaging infrastructure and is not subject to the security vulnerabilities of existing bridging solutions.
04
OFT Functionality
OFTs use LayerZero’s generic messaging primitive to allow applications deployed on multiple chains to transfer token balances to one another. This means that any fungible token can become an OFT and avoid the need to build for multiple conflicting blockchain standards. OFTs are instantly unified across all chains they are deployed on.
05
OFT Advantages
OFTs have major advantages over existing solutions built across multiple blockchain standards, including:



  • Security: Generic cross-chain messaging is a major improvement in overall security compared to existing middlechain and wrapped asset bridge solutions; transferred tokens are being issued by 1st party contracts on destination chains vs. 3rd party contracts with vulnerable wrapped assets.



  • Standardization: Token balances can move across chains and remain in their native form without the need to develop for countless standards (ex. ERC20, BEP20, SPL20).



  • Efficiency: All OFTs exist as native tokens and are completely free to use with the exception of gas costs. No bridging fees and efficient arbitrage across chains make OFTs the clear choice for omnichain tokens.



  • Unified Liquidity: Balances of OFT tokens can be modified seamlessly across chains resulting in truly unified liquidity without the fragmentation of existing solutions.



  • Composability: The OFT standard allows other decentralized applications to quickly integrate with omnichain tokens; all interactions and calls are easily accessible so long as an application has the token address (ex. Rapid integration with AMMs and exchanges).
06
Bridge Functionality
The BTC.b bridge allows users to securely transfer omnichain Bitcoin between Ethereum, BSC, Arbitrum, Optimism, Fantom, Avalanche, and Aptos. Users can securely transfer omnichain BTC.b tokens between chains using LayerZero’s messaging protocol and the OFT Standard. Remember, transferring BTC.b to non-EVM chains such as Aptos for the first time requires additional steps which are detailed below.
07
Transferring BTC.b to Non-EVM Chains (Ex. Aptos)
Registering & Claiming Assets
When sending BTC.b from a non-Aptos wallet to a destination Aptos wallet, users will be required to register and/or claim their BTC on Aptos. This is a result of the fundamental design differences between Aptos and other blockchains that are designed to enhance security.
Transferring Assets to Aptos for the First Time
Transferring BTC.b to Aptos wallets requires registration and claim transactions. This is done to enhance user security and is unique to Aptos.



Scenario 1: Users have gas assets available on the destination Aptos Wallet In this scenario, users transferring assets will be prompted to register their BTC.b on their Aptos wallet if it has not already been registered. Users will not be required to submit an additional claim transaction in this scenario.



Scenario 2: Users do not have gas assets available on the destination Aptos Wallet If a user does not have gas assets available on their destination wallet they will only have to claim their BTC.b once the transaction is finished. Users will receive APT tokens (for gas fees) on the destination wallet to pay for the cost of claiming their assets. This APT is paid for by the user on the source wallet and is transferred through to the destination.



Remember, these registration and claim requirements only apply when a user interacts with a token for the first time. Follow up transfers of the same token will not require these transactions.
Transferring Assets from Aptos to Other Chains
Transferring BTC.b from Aptos back to other chains (ex. Ethereum) does not require additional registration or claim transactions. Transfers out of Aptos are subject to a 2 to 3 day waiting period before the transaction is completed. This waiting period is for security purposes and allows for a significant number of blocks to be finalized before relaying messages to non-Aptos chains.
08
How to acquire BTC.b
  1. Buy BTC / Own BTC
  2. Download Core browser extension / Use Core web
  3. Transfer BTC to Core BTC addresses
  4. Bridge BTC using Core and receive BTC.b on EVM C-Chain address
  5. Connect Core to dApp with BTC.b / Transfer to chain of choice via https://bitcoinbridge.network/
  6. Use BTC.b as liquidity, in a vault, for trade, etc.