Questions tagged [musig]
MuSig is a family of protocols for aggregating public keys and signatures. It includes MuSig (also called MuSig1), MuSig2 and MuSig-DN. Key and signature aggregation makes multisignature transactions cheaper and more private.
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Do we need a taproot commit for multisignatures if there is no script path, but we are using the MuSig2 protocol?
I read in some article for Taproot that if there is no need for a script path spending and a number of participant (multisignature with key aggregation) create together a taproot output key (key for a ...
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How can I tell if a Taproot input is a key path spend or a script path spend?
In some analyses of chain activity, I sometimes see Taproot spends divided into key path and script path.
Why are they called that?
Which BIPs should I read to learn more?
When I look at a P2TR tx in ...
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What's cheaper, musig or multisig?
Taproot transactions aren't always cheaper onchain compared to their segwit native counterparts. How does the current MuSig spec fare compared to multisig onchain? Is one always cheaper than the other ...
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To what extent does BIP32 key derivation impact the design of secure key aggregation multisig and threshold schemes like MuSig and FROST?
I have seen it discussed in various places (e.g. 1, 2) that using BIP32 key derivation impacts the design of secure key aggregation multisig and threshold schemes like MuSig(2) and FROST.
What are the ...
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What is the argument for not using proofs of possession in Bitcoin multisig and threshold key aggregation schemes?
A number of multisig and threshold sig key aggregation schemes developed outside of the Bitcoin ecosystem (e.g. SpeedyMuSig, FROST) use proofs of possession yet those developed in the Bitcoin ...
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What's not standard in these descriptors?
In here, about these (indentation is mine):
sh(wsh(multi(2, abcdef01/1'/1'/0/*, 23456789/1'/1'/0/*)))#abcdefgh
sh(wsh(multi(2, abcdef01/1'/1'/1/*, 23456789/1'/1'/1/*)))#ijklmnop
wsh(multi(2, ...
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musig2 with BIP-32 style nonce chain
I am interested in the case where a fixed pool of signers will sign a series of many messages. As I understand it, musig2 would allow pre-processing, whereby a signature aggregator could collect a ...
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Why does only one of the two nonce points in MuSig2 have the exponent b?
In MuSig2 R''_i is added to itself b times (in multiplicative notation, it has the exponent b) but R'_i is not (it does not have the exponent b).
Why does only one of the nonce points have the ...
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In MuSig2 how is multiplication of coordinates defined?
In the MuSig2 paper each signer multiplies all the nonces together (in the naive version):
R_1 * R_2 * R_3 * .... R_n
where R_i = r_i * G. r_i is a scalar and G is the generator point (coordinate) ...
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How does SpeedyMuSig compare to MuSig2?
This paper (Crites, Komlo, Maller) on the security of Schnorr multisig and threshold signature schemes introduces a new variant of MuSig2 called SpeedyMuSig that includes proofs of possession and ...
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How do MuSig2 and FROST compare for multisig key aggregation schemes?
Although FROST is primarily for threshold (k-of-n, k<n) key aggregation schemes (and MuSig2 doesn't support threshold) FROST can support multisig (n-of-n) key aggregation. So what are the upsides ...
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How do the various Lightning implementations treat latency? How long do they wait for a peer to provide a signature before using unhappy path?
Rene Pickhardt brought up the problem of latency on the Lightning Network in this answer on using nested (or "recursive") MuSig2 or FROST when providing a signature within an existing ...
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Can you do P2WSH / P2SH on Lightning Network (LN)?
I understand that a channel is a 2 of 2 multisig:
1 && 1
Is it possible that one side of this channel is a multisig wallet?
So in essence one of the 2 main, is actually a 2 of 3 multisig. ...
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With MuSig2 can we now avoid any privacy leak of a Lightning channel's onchain UTXO?
Now we have access to Schnorr and MuSig(2) onchain can we avoid any privacy leak of a Lightning channel's associated onchain UTXO?
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Where can I get some MuSig2 test vectors?
I am writing a MuSig2 library and need some test vectors. This should include the hash functions used.
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How to spend a taproot output using key path with a threshold signature scheme when the secret key is never computed?
In taproot, in order to spend the keypath, the transaction must be signed using the tweaked private key instead of the normal private key (as defined in BIP 341).
However when computing a signature ...
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Possible number of signers with MuSig
With multisig, up to 20 signatures may be used in a threshold signature scheme (What are the limits of m and n in m-of-n multisig addresses?).
As far as I understand, there should be no hard-coded ...
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Taproot, potential quantum bug, and general clarification
Here seeking information. I have 2 questions marked with parens
Would like some clarification pertaining to the Mark Friedenbach article:
Why I'm Against Taproot
The point of contention with Mark ...
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What is the difference between key aggregation and signature aggregation?
What is the difference between key aggregation (e.g. MuSig) and signature aggregation?
Many people (including myself) have in the past used these terms interchangeably. Why is it important to be ...
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Using key aggregation (multsig) in P2TR script path spends
I know that it is possible to create a 2-2 multsig using Taproot by combining both private keys into one public key and defining that as the key path spend. I also know that it is possible to use ...
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Why is Public Key aggregation in MuSig described as a product of the public keys?
In the the MuSig2 paper, it is described that:
Each signer randomly generates and communicates to others a nonce
Ri=g^ri; then, each of them computes R=∏ni=1Ri,c=H( ̃X,R,m)where
̃X=∏ni=1Xiis the ...
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In MuSig-DN why not use a truly random number for the nonce instead of a pseudorandom function?
In MuSig-DN why not use a truly random number for the nonce instead of a pseudorandom function (PRF)? If the nonce space is big enough it would never be reused.
This question was asked by emzy on ...
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Who will the first adopters of Taproot be (assuming it is activated at some stage)? What incentives are there to start using it straight away?
Adoption of SegWit by users and companies after it was activated was slow. Should we expect adoption of Taproot to be slow also (assuming it is activated at some stage)?
Who will the first adopters of ...
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Which MuSig scheme is optimal? Classic MuSig or this new MuSig-DN scheme?
Now we have two competing MuSig schemes which is better? Classic MuSig or MuSig-DN? Which use case(s) might choose classic MuSig over MuSig-DN and vice versa?
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Schnorr without R in the challenge
I read the Schnorr and MuSig papers and stumbled over the problem that the use of deterministic nonces in multisignatures is not safe. The adversary would be able to extract the private key from the ...
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Is Z-man's PTLC construction implementable using libsecp256k1-zkp?
In a mailing list post Z-man details a PTLC construction which he claims is "is almost entirely a MuSig ritual". My question is whether this MusigTweak is what is called the adaptor (last argument of ...
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Musig Signature Interactivity
2 Questions:
Why is Musig signing always interactive?
Let's say I have a Musig wallet where keys are stored in secure locations with no internet access. What are some methods to sign from these ...
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How could Schnorr signatures be aggregated across the whole transaction?
I am studying the MuSig protocol and am having trouble grasping certain segments. This is my understanding thus far:
In current Bitcoin CHECKMULTISIG format, the size of the signature grows linearly ...
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Does MuSig have the same security as 2-2 multisig?
Disclaimer: This question is of theoretical importance to me trying to educate myself better on cryptographic principles and signature schemes. I don't intend to imply that in practice schnorr ...
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Can R/r in Musig be derived from only seeds and message hashes?
I am wondering if the first two roundtrips of pre-committing and then revealing R/r in MuSig signing can be moved to the keygen phase and made deterministic. That reduces the amount of messages that ...
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Can i compose a multisig address where one of the signatories is a multisig address?
Can i compose a multisig address where one of the signatories is a multisig address?
In order to create a multisig address we need the pubkey of the signatories.
bitcoincli addmultisigaddress 2
'["...
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How does schnorr signature construct multisig functionality?
How does the multiparty schnorr signature work and enable multisig
functionality in Bitcoin?
What are its limitations? Can we construct any m of n signature?
Is there anyway to hide the signers among ...
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