<unnamed>

Public Key

npub1pcahv5ukvgeh99knz2yrdd2sku460cqme8qu49xqz88hrtsfu0sskrcqst

Profile Code

nprofile1qqsquwmk2wtxyvmjjmf39zpkk4gtw2a8uqdunsw2jnqprnm34cy78cgpz3mhxue69uhhyetvv9ujuerpd46hxtnfduqs6amnwvaz7tmwdaejumr0dsl2zthq

Publishing to

nostr.wine

nos.lol

relay.damus.io

Last Notes

2023-06-07 18:17:00 UTC

- reply

📅 Original date posted:2019-03-12
📝 Original message:Dear Gregory,
First of all, I would like to express my deep appreciation to your entire
craft in the FOSS ecosystem, specially in Bitcoin, even more In Blockstream.
I think you are a brilliant engineer and very principled leader. your
efforts are an inspiration for many, a truly enduring forever mark in
history of FOSS.
I've submitted fixes to your concerns here:
https://github.com/bitcoin/bips/commit/b63ed0e17e872b7e7b8634591b0ddfa3dedfdc73#diff-deacf3a22d788a10ce12e4d92ee814ff
Would appreciate your review.
On other note, I still think that this security fix is redundant, I believe
CKD function (BIP32) does encapsulate sufficient amount of entropy, but due
to lack of formal knowledge and assistance, I've not managed to get formal
proof, so I fallback'ed to add this patch for security reasons.
Best regards,
Omar
On Fri, Sep 1, 2017 at 10:16 AM Omar Shibli <omarshib at gmail.com> wrote:
> Hello Gregory,
>
> Thanks for you feedback.
>
> The BIP has been updated to explicitly specify the multiparty key
> derivation scheme which hopefully addresses your concerns.
>
> Please have a look at the updated draft of the BIP at the link below:
>
>
> https://github.com/commerceblock/pay-to-contract-protocol-specification/blob/master/bip-draft.mediawiki
>
> Any feedback is highly appreciated.
>
> Regards,
> Omar
>
> On Tue, Aug 15, 2017 at 7:40 PM, omar shibli <omarshib at gmail.com> wrote:
>
>> Thank you for your time Gregory, I really appreciate that.
>>
>> What we are describing here is a method to embed cryptographic signatures
>> into a public key based on HD Wallets - BIP32.
>> In a practical application, we should have two cryptographic signatures
>> from both sides, I don't think in that case your scenario would be an issue.
>>
>> More specifically in our application, we do the following construction:
>>
>> contract base: m/200'/0'/<contract_number>'
>> payment base (merchant commitment):
>> contract_base/<merchant_contract_signature>
>> payment address (customer commitment):
>> contract_base/<merchant_contract_signature>/<customer_contract_signature>
>>
>> payment address funds could be reclaimed only if the
>> customer_contract_signature is provided by the customer.
>>
>> In terms of durability, our app is pretty simple at this point, we don't
>> store anything, we let customer download and manage the files.
>>
>> I will update the BIP to address your concerns.
>>
>> On Tue, Aug 15, 2017 at 8:12 AM, Gregory Maxwell <greg at xiph.org> wrote:
>>
>>> This construction appears to me to be completely insecure.
>>>
>>>
>>> Say my pubkey (the result of the derivation path) is P.
>>>
>>> We agree to contract C1. A payment is made to P + G*H(C1).
>>>
>>> But in secret, I constructed contract C2 and pubkey Q and set P = Q +
>>> G*H(C2).
>>>
>>> Now I can take that payment (paid to Q + G*(C1) + G*H(C2)) and assert
>>> it was in act a payment to P' + G*H(C2). (P' is simply Q + G*H(C1))
>>>
>>> I don't see anything in the proposal that addresses this. Am I missing
>>> it?
>>>
>>> The applications are also not clear to me, and it doesn't appear to
>>> address durability issues (how do you avoid losing your funds if you
>>> lose the exact contract?).
>>>
>>>
>>>
>>>
>>> On Mon, Aug 14, 2017 at 6:05 AM, omar shibli via bitcoin-dev
>>> <bitcoin-dev at lists.linuxfoundation.org> wrote:
>>> > Hey all,
>>> >
>>> > A lot of us familiar with the pay to contract protocol, and how it uses
>>> > cleverly the homomorphic property of elliptic curve encryption system
>>> to
>>> > achieve it.
>>> > Unfortunately, there is no standard specification on how to conduct
>>> such
>>> > transactions in the cyberspace.
>>> >
>>> > We have developed a basic trade finance application that relies on the
>>> > original idea described in the Homomorphic Payment Addresses and the
>>> > Pay-to-Contract Protocol paper, yet we have generalized it and made it
>>> BIP43
>>> > complaint.
>>> >
>>> > We would like to share our method, and get your feedback about it,
>>> hopefully
>>> > this effort will result into a standard for the benefit of the
>>> community.
>>> >
>>> > Abstract idea:
>>> >
>>> > We define the following levels in BIP32 path.
>>> > m / purpose' / coin_type' / contract_id' / *
>>> >
>>> > contract_id is is an arbitrary number within the valid range of
>>> indices.
>>> >
>>> > Then we define, contract base as following prefix:
>>> > m / purpose' / coin_type' / contract_id'
>>> >
>>> > contract commitment address is computed as follows:
>>> > hash document using cryptographic hash function of your choice (e.g.
>>> blake2)
>>> > map hash to partial derivation path
>>> > Convert hash to binary array.
>>> > Partition the array into parts, each part length should be 16.
>>> > Convert each part to integer in decimal format.
>>> > Convert each integer to string.
>>> > Join all strings with slash `/`.
>>> > compute child public key by chaining the derivation path from step 2
>>> with
>>> > contract base:
>>> > m/<contract_base>/<hash_derivation_path>
>>> > compute address
>>> > Example:
>>> >
>>> > master private extended key:
>>> >
>>> xprv9s21ZrQH143K2JF8RafpqtKiTbsbaxEeUaMnNHsm5o6wCW3z8ySyH4UxFVSfZ8n7ESu7fgir8imbZKLYVBxFPND1pniTZ81vKfd45EHKX73
>>> > coin type: 0
>>> > contract id: 7777777
>>> >
>>> > contract base computation :
>>> >
>>> > derivation path:
>>> > m/999'/0'/7777777'
>>> > contract base public extended key:
>>> >
>>> xpub6CMCS9rY5GKdkWWyoeXEbmJmxGgDcbihofyARxucufdw7k3oc1JNnniiD5H2HynKBwhaem4KnPTue6s9R2tcroqkHv7vpLFBgbKRDwM5WEE
>>> >
>>> > Contract content:
>>> > foo
>>> >
>>> > Contract sha256 signature:
>>> > 2c26b46b68ffc68ff99b453c1d30413413422d706483bfa0f98a5e886266e7ae
>>> >
>>> > Contract partial derivation path:
>>> >
>>> 11302/46187/26879/50831/63899/17724/7472/16692/4930/11632/25731/49056/63882/24200/25190/59310
>>> >
>>> > Contract commitment pub key path:
>>> >
>>> m/999'/0'/7777777'/11302/46187/26879/50831/63899/17724/7472/16692/4930/11632/25731/49056/63882/24200/25190/59310
>>> > or
>>> >
>>> <contract_base_extended_pub_key>/11302/46187/26879/50831/63899/17724/7472/16692/4930/11632/25731/49056/63882/24200/25190/59310
>>> >
>>> > Contract commitment pub key:
>>> >
>>> xpub6iQVNpbZxdf9QJC8mGmz7cd3Cswt2itcQofZbKmyka5jdvQKQCqYSDFj8KCmRm4GBvcQW8gaFmDGAfDyz887msEGqxb6Pz4YUdEH8gFuaiS
>>> >
>>> > Contract commitment address:
>>> > 17yTyx1gXPPkEUN1Q6Tg3gPFTK4dhvmM5R
>>> >
>>> >
>>> > You can find the full BIP draft in the following link:
>>> >
>>> https://github.com/commerceblock/pay-to-contract-protocol-specification/blob/master/bip-draft.mediawiki
>>> >
>>> >
>>> > Regards,
>>> > Omar
>>> >
>>> > _______________________________________________
>>> > bitcoin-dev mailing list
>>> > bitcoin-dev at lists.linuxfoundation.org
>>> > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
>>> >
>>>
>>
>>
>
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2023-06-07 18:06:28 UTC

- reply

📅 Original date posted:2017-09-29
📝 Original message:Thank you for sharing, this is indefinitely valuable.
I think that risk could be mitigated if instead of ignoring the bitcoin
address/amount/..., the wallet use this address for integrity checks.
Furthermore, I think this BIP could be improved by actually applying the
homomorphic property and deriving the bitcoin address from merchant pub key
and the hash itself. that would allow both the customer and merchant to be
able generate address independently.
On Fri, Sep 29, 2017 at 5:55 AM, Peter Todd via bitcoin-dev <
bitcoin-dev at lists.linuxfoundation.org> wrote:
> On Thu, Sep 28, 2017 at 03:43:05PM +0300, Sjors Provoost via bitcoin-dev
> wrote:
> > Andreas Schildbach wrote:
> > > This feels redundant to me; the payment protocol already has an
> > > expiration time.
> >
> > The BIP-70 payment protocol has significant overhead and most
> importantly requires back and forth. Emailing a bitcoin address or printing
> it on an invoice is much easier, so I would expect people to keep doing
> that.
>
> The BIP-70 payment protocol used via BIP-72 URI's is insecure, as payment
> qr
> codes don't cryptographically commit to the identity of the merchant, which
> means a MITM attacker can redirect the payment if they can obtain a SSL
> cert
> that the wallet accepts.
>
> For example, if I have a wallet on my phone and go to pay a
> merchant, a BIP-72 URI will look like the following(1):
>
> bitcoin:mq7se9wy2egettFxPbmn99cK8v5AFq55Lx?amount=0.11&r=https://
> merchant.com/pay.php?h%3D2a8628fc2fbe
>
> A wallet following the BIP-72 standard will "ignore the bitcoin
> address/amount/label/message in the URI and instead fetch a PaymentRequest
> message and then follow the payment protocol, as described in BIP 70."
>
> So my phone will make a second connection - likely on a second network
> with a
> totally different set of MITM attackers - to https://merchant.com
>
> In short, while my browser may have gotten the correct URL with the correct
> Bitcoin address, by using the payment protocol my wallet is discarding that
> information and giving MITM attackers a second chance at redirecting my
> payment
> to them. That wallet is also likely using an off-the-shelf SSL library,
> with
> nothing other than an infrequently updated set of root certificates to use
> to
> verify the certificate; your browser has access to a whole host of better
> technologies, such as HSTS pinning, certificate transparency, and
> frequently
> updated root certificate lists with proper revocation (see Symantec).
>
> As an ad-hoc, unstandardized, extension Android Wallet for Bitcoin at least
> supports a h= parameter with a hash commitment to what the payment request
> should be, and will reject the MITM attacker if that hash doesn't match.
> But
> that's not actually in the standard itself, and as far as I can tell has
> never
> been made into a BIP.
>
> As-is BIP-72 is very dangerous and should be depreciated, with a new BIP
> made
> to replace it.
>
> 1) As an aside, it's absolutely hilarious that this URL taken straight from
> BIP-72 has the merchant using PHP, given its truly terrible track
> record for
> security.
>
> --
> https://petertodd.org 'peter'[:-1]@petertodd.org
>
> _______________________________________________
> bitcoin-dev mailing list
> bitcoin-dev at lists.linuxfoundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
>
>
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2023-06-07 18:06:14 UTC

- reply

📅 Original date posted:2017-09-26
📝 Original message:According to my understanding, Bitcoin protocol is a combination of several
components (node, miner, wallet..), you can use different licenses for
different components, as long as the components are well structured and
inter APIs are well defined and encapsulated, therefore, incompatible
licenses could be not an issue.
Please note that I'm not legal advisor and this is just my personal opinion.
On Tue, Sep 26, 2017 at 12:53 AM, Radcliffe, Mark via bitcoin-dev <
bitcoin-dev at lists.linuxfoundation.org> wrote:
> My apologies if this post has been answered, but I am new to the list. I
> am lawyer trying to understand the licensing of the Bitcoin core and I
> will be presenting in a webinar with Black Duck Software on Blockchain on
> September 28 (in case you are not familiar with them, Black Duck Software
> assists companies in managing their open source software resources). They
> have scanned the Bitcoin Core code for the open source licenses used in the
> codebase. I am enclosing a summary of the findings. I would be interested
> in communicating with the individuals who manage this codebase and can
> provide insight about the project manages contributions because the
> codebase includes projects with inconsistent licenses (for example, code
> licensed under the Apache Software License version 2 and GPLv2 cannot work
> together in some situations). Thanks in advance.
>
>
>
> According to the scan, the code base includes code licensed under the
> following licenses:
>
>
>
> Apache License 2.0
>
> Boost Software License 1.0
>
> BSD 2-clause "Simplified" License
>
> BSD 3-clause "New" or "Revised" License
>
> Creative Commons Attribution Share Alike 3.0
>
> Expat License
>
> GNU General Public License v2.0 or later
>
> GNU General Public License v3.0 or later
>
> GNU Lesser General Public License v2.1 or later
>
> License for A fast alternative to the modulo reduction
>
> License for atomic by Timm Kosse
>
> MIT License
>
> Public Domain
>
> University of Illinois/NCSA Open Source License
>
>
>
>
>
>
>
>
>
> *Mark Radcliffe*
> Partner
>
>
> *T* +1 650.833.2266 <(650)%20833-2266>
> *F* +1 650.687.1222 <(650)%20687-1222>
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> *E* mark.radcliffe at dlapiper.com
>
>
>
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