Published on: 2021-05-15T20:35:37+00:00
On May 15, 2021, the bitcoin-dev mailing list saw a discussion about Taproot's ability to produce a signature matching the sum of public keys used in Taproot. Vjudeu initially suggested that this would be possible, but Tim Ruffing corrected this statement by asserting that Taproot does not enable cross-input aggregation or the ability to spend multiple UTXOs with a single signature.To further the discussion, Ruben recommended reading about MuSig, a key aggregation scheme that utilizes Schnorr signatures. The provided link directs to a Blockstream blog post that provides detailed information on MuSig.In the context of Taproot security, the scenario of Bob attempting to steal Alice's coins was discussed. Bob knows Alice's public key "a*G" and creates a taproot address "(b-a)*G" to receive a small amount of funds. Bob then crafts a transaction with two inputs, taking coins from both "a*G" and "(b-a)*G" addresses. He needs to produce a signature that matches the sum of the public keys used in taproot, which simplifies to "b*G". Bob uses his private key "b" to generate a Schnorr signature.However, there are potential protections against such attacks. One solution involves implementing a multisignature setup, requiring both Alice and Bob to sign off on any transactions. Another approach is to employ a timelock, enabling Alice to delay transactions for a certain period of time. Additionally, Alice can utilize coin control features to safeguard her coins from these types of attacks.It is crucial for users to be aware of these potential risks and take appropriate precautions to protect their assets when utilizing Taproot technology.
Updated on: 2023-08-02T03:52:03.303430+00:00