Is it Safe to Use a Private Key for an Existing SingleSig Wallet as One of the Keys for a New Multisig Wallet?
As a self-custody enthusiast, I’ve been exploring various options for managing my digital assets securely. Recently, I came across Blockstream Jade and air-gapped keys, which have piqued my interest in decentralized storage solutions like multisig wallets. One question that has crossed my mind is whether it’s safe to use an existing SingleSigner (SSG) wallet key as one of the private keys for a new multisig wallet.
The Risks of Using Existing Keys
While SSGs are designed to be secure, using them as keys for a new multisig wallet does come with some risks. Here are a few considerations:
- Key exposure: When you use an existing key from your SingleSigner wallet, it becomes accessible to anyone who has physical access to the hardware or software. This is particularly concerning if you store sensitive information like private keys in plain sight.
- Wallet compromise: If someone gains unauthorized access to your air-gapped hardware or software, they may also gain access to your SSG keys and other sensitive data stored within the wallet.
- Private key management complexity: Using multiple keys for a multisig wallet can add complexity to private key management. You’ll need to keep track of multiple keys and ensure that each one is secure and not compromised.
The Benefits of Using Existing Keys
On the other hand, using an existing SSG key as one of the private keys for a new multisig wallet offers some benefits:
- Existing infrastructure: If you already have air-gapped hardware or software, using your SingleSigner keys can leverage that existing infrastructure to reduce the complexity of private key management.
- Reduced risk of loss: With an existing key from your SSG wallet, there’s a lower risk of losing it compared to a new, untested key.
Mitigating Risks
To minimize risks when using existing keys for a new multisig wallet:
- Use hardware security measures: Ensure that all air-gapped hardware and software are properly secured, including physical access controls, encryption, and secure boot mechanisms.
- Keep your SSG wallet and keys isolated: Store the SingleSigner wallet and its associated key(s) in a separate, tamper-evident container to prevent accidental exposure.
- Use a secure storage solution: Consider using a secure storage solution like Hardware Security Module (HSM) or a trusted execution environment (TEE) to store your SSG keys.
- Regularly monitor and update
: Periodically review the security posture of both wallets and ensure that all key management practices are up-to-date.
Conclusion
While there are some risks associated with using existing SingleSigner wallet keys as private keys for a new multisig wallet, careful planning, mitigation strategies, and secure storage solutions can help minimize these risks. As you explore decentralized storage solutions like Blockstream Jade and multisig wallets, be sure to weigh the benefits against the potential drawbacks and take steps to ensure your digital assets remain safe.
Recommendations
If you’re considering using an existing SSG key for a new multisig wallet, I recommend taking the following steps:
- Evaluate your security posture: Assess your air-gapped hardware and software infrastructure to identify any vulnerabilities that could impact private key management.
- Use secure storage solutions: Consider using HSMs or TEEs to store sensitive data like SSG keys.
- Monitor and update practices: Regularly review and update your key management practices to ensure they remain secure.