Re: [bitcoin-dev] BIP174 extension proposal (Global Type: PSBT_GLOBAL_XPUB_SIGNATURE)

2019-06-28 Thread Dmitry Petukhov via bitcoin-dev
In your proposed field key format, {0x02}|{signing_pubkey}|{m}|{xpub}|...|{xpub} I think you can replace the signing pubkey with just a fingerprint of the master key, that would save 29 bytes per 0x02 field. If the only entity that is concerned about the validity of the signature is those that

Re: [bitcoin-dev] Generalized covenants with taproot enable riskless or risky lending, prevent credit inflation through fractional reserve

2019-06-28 Thread Tamas Blummer via bitcoin-dev
Hi Eric, Thank you for your questions as they show what concepts need further explanation, so you understand the potential of this proposal and how it is helpful to the ecosystem. Riskless zero bond is in fact the most basic concept of financial engineering. Yes, there are engineers of

Re: [bitcoin-dev] Generalized covenants with taproot enable riskless or risky lending, prevent credit inflation through fractional reserve

2019-06-28 Thread Eric Voskuil via bitcoin-dev
Hi Tamas, There are a number of economic assumptions contained herein. While I understand you would like to focus on implementation, the worst bugs are requirements bugs. IMO these should be addressed first. I’ve addressed some possible issues inline. > On Jun 28, 2019, at 01:27, Tamas

Re: [bitcoin-dev] BIP174 extension proposal (Global Type: PSBT_GLOBAL_XPUB_SIGNATURE)

2019-06-28 Thread Jonathan Underwood via bitcoin-dev
Thanks for the reply Peter. Comments inline: 2019年6月28日(金) 23:37 Peter D. Gray : > Thanks I get the idea better now: You want the PSBT creator to be > able to indicate to the signers that it (the PSBT creator) controls > specific outputs that don't otherwise look like change. > > Some problems:

[bitcoin-dev] Generalized covenants with taproot enable riskless or risky lending, prevent credit inflation through fractional reserve

2019-06-28 Thread Tamas Blummer via bitcoin-dev
I start with a formalisation of loans as common in finance: A zero bond is a contract between two parties Alice and Bob whereby Alice receives an amount less than P and has to pay back P at a later time point called maturity. The difference between the amount received and P is the interest

Re: [bitcoin-dev] BIP174 extension proposal (Global Type: PSBT_GLOBAL_XPUB_SIGNATURE)

2019-06-28 Thread Peter D. Gray via bitcoin-dev
Thanks I get the idea better now: You want the PSBT creator to be able to indicate to the signers that it (the PSBT creator) controls specific outputs that don't otherwise look like change. Some problems: > extended private key of the current signer derived from the > signer's root to

Re: [bitcoin-dev] Taproot proposal

2019-06-28 Thread Russell O'Connor via bitcoin-dev
Hmm? If I'm following what you mean, that's not the P2P rules, it's the > Unserialize code, in particular: > > compat/assumptions.h:52:static_assert(sizeof(int) == 4, "32-bit int > assumed"); > > serialize.h:289:uint64_t ReadCompactSize(Stream& is) > > serialize.h-679-template typename V> >

Re: [bitcoin-dev] Taproot proposal

2019-06-28 Thread Anthony Towns via bitcoin-dev
On Wed, Jun 26, 2019 at 08:08:01PM -0400, Russell O'Connor via bitcoin-dev wrote: > I have a comment about the 'input_index' of the transaction digest for taproot > signatures.  It is currently listed as 2 bytes.  I think it would be better to > expand that to 4 bytes. FWIW, I think this would