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multiple new BIP proposals coming up on day 2 of scaling bitcoin HK

Day 2 is where the BIP proposals are being presented:
09:05 HKT "Segregated witness and its impact on scalability" Pieter Wuille pwuille
seg-witness transcript: http://diyhpl.us/wiki/transcripts/scalingbitcoin/hong-kong/segregated-witness-and-its-impact-on-scalability/
seg-witness slides: https://prezi.com/lyghixkrguao/segregated-witness-and-deploying-it-for-bitcoin/
seg-witness BIP code: https://github.com/sipa/bitcoin/commits/segwit
12:10 HKT "A bevy of block size proposals: 100, 102 and more." Jeff Garzik jgarzik
BIP survey slides: http://www.slideshare.net/jgarzik/a-bevy-of-block-size-proposals-scaling-bitcoin-hk-2015
survey transcript: http://diyhpl.us/wiki/transcripts/scalingbitcoin/hong-kong/a-bevy-of-block-size-proposals-bip100-bip102-and-more/
12:45 HTK "A flexible limit: Trading subsidy for larger blocks" Mark Friedenbach maaku7
flexcap BIP transcript: http://diyhpl.us/wiki/transcripts/scalingbitcoin/hong-kong/a-flexible-limit-trading-subsidy-for-larger-blocks/
livestreams: https://scalingbitcoin.org/hongkong2015/live
IRC questions/discussion: #bitcoin-workshops
submitted by adam3us to Bitcoin [link] [comments]

I keep reading people say bitcoin development is stalled

But in practice there's more going on right now than there's ever been in the last few years. You just have to look in the right places. Here's a few days of documented github activity from the bitcoin slack and I've a feeling there are hundreds more people working on Bitcoin projects outside of the work being done by core:
github BOT [6:28 PM] [bitcoin:master] 2 new commits by Daniel Kraft and 1 other: f93c2a1 net: Avoid duplicate getheaders requests. - Daniel Kraft 8e8bebc Merge #8054: net: Avoid duplicate getheaders requests. - Wladimir J. van der Laan
[6:28] [bitcoin/bitcoin] Pull request closed: #8054 net: Avoid duplicate getheaders requests. by laanwj
[6:31] [bitcoin:master] 6 new commits by Pieter Wuille and 1 other: d253ec4 Make ProcessNewBlock dbp const and update comment - Pieter Wuille 316623f Switch reindexing to AcceptBlock in-loop and ActivateBestChain afterwards - Pieter Wuille fb8fad1 Optimize ActivateBestChain for long chains - Pieter Wuille d3d7547 Add -reindex-chainstate that does not rebuild block index - Pieter Wuille b4d24e1 Report reindexing progress in GUI - Pieter Wuille Show more...
[6:31] [bitcoin/bitcoin] Pull request closed: #7917 Optimize reindex by laanwj
Joshua Unseth [9:55 PM] joined #commit-activity. Also, @sjors joined and left.
----- May 19th -----
github BOT [12:08 AM] [bitcoin/bitcoin] Pull request submitted by EthanHeilman

8070 Remove non-determinism which is breaking net_tests #8069

If addrmanUncorrupted does not have the same nKey every time it will map addrs to different bucket positions and occasionally cause a collision between two addrs, breaking the test.
github BOT [1:00 AM] [bitcoin/bitcoin] Pull request closed: #7716 [0.11] Backport BIP9 and softfork for BIP's 68,112,113 by morcos
Eragmus You Should Probably Stop Modding [1:12 AM] joined #commit-activity. Also, @buttmunch joined, @icandothisallday joined, @misnomer joined, @coreneedstostop joined, @xchins joined, @jbeener joined, @jbleeks joined, @whalepanda joined, @grinny joined, @alex_may joined, @mr_e joined.
github BOT [2:46 PM] [bitcoin:master] 5 new commits by Warren Togami and 1 other: 00678bd Make failures to connect via Socks5() more informative and less unnecessarily scary. - Warren Togami 0d9af79 SOCKS5 connecting and connected messages with -debug=net. - Warren Togami 94fd1d8 Make Socks5() InterruptibleRecv() timeout/failures informative. - Warren Togami bf9266e Use Socks5ErrorString() to decode error responses from socks proxy. - Warren Togami 18436d8 Merge #8033: Fix Socks5() connect failures to be less noisy and less unnecessarily scary - Wladimir J. Show more...
[2:46] [bitcoin/bitcoin] Pull request closed: #8033 Fix Socks5() connect failures to be less noisy and less unnecessarily scary by laanwj
github BOT [3:56 PM] [bitcoin:master] 3 new commits by EthanHeilman and 2 others: f4119c6 Remove non-determinism which is breaking net_tests #8069 - EthanHeilman 2a8b358 Fix typo adddrman to addrman as requested in #8070 - Ethan Heilman 7771aa5 Merge #8070: Remove non-determinism which is breaking net_tests #8069 - Wladimir J. van der Laan
[3:56] [bitcoin/bitcoin] Pull request closed: #8070 Remove non-determinism which is breaking net_tests #8069 by laanwj
github BOT [5:18 PM] [bitcoin/bitcoin] Pull request submitted by MarcoFalke

8072 travis: 'make check' in parallel and verbose

• 'make check' in parallel, since the log will take care of clean output • 'make check' verbose, so that test failure causes aren't hidden
Fixes: #8071
github BOT [7:56 PM] [bitcoin/bitcoin] Pull request submitted by rat4

8073 qt: askpassphrasedialog: Clear pass fields on accept

This is usability improvement in a case if user gets re-asked passphrase. (e.g. made a typo)
Victor Broman [8:01 PM] joined #commit-activity. Also, @bb joined, @ziiip joined.
----- May 20th -----
github BOT [12:34 PM] [bitcoin/bitcoin] Pull request submitted by jsantos4you

8075 0.12

debug.data.txt
[12:37] [bitcoin/bitcoin] Pull request closed: #8075 0.12 by sipa
github BOT [3:37 PM] [bitcoin/bitcoin] Pull request closed: #7082 Do not absolutely protect local peers and make eviction more aggressive. by gmaxwell
github BOT [3:44 PM] [bitcoin:master] 2 new commits by Cory Fields and 1 other: 401ae65 travis: 'make check' in parallel and verbose - Cory Fields 1b87e5b Merge #8072: travis: 'make check' in parallel and verbose - MarcoFalke
[3:44] [bitcoin/bitcoin] Pull request closed: #8072 travis: 'make check' in parallel and verbose by MarcoFalke
github BOT [3:58 PM] [bitcoin/bitcoin] Pull request closed: #7093 Address mempool information leak and resource wasting attacks. by gmaxwell
github BOT [6:11 PM] [bitcoin/bitcoin] Pull request submitted by sdaftuar

8076 VerifyDB: don't check blocks that have been pruned

If a pruning node ends up in a state where it has very few blocks on disk, then a node could fail to start up in VerifyDB. This pull changes the behavior for pruning nodes, so that we will just not bother trying to check blocks that have been pruned.
I don't expect this edge case to be triggered much in practice currently; this is a preparatory commit for segwit (to deal with the case of pruning nodes that upgrade after segwit activation).
@sipa
Erik Hedman [6:20 PM] joined #commit-activity
github BOT [8:46 PM] [bitcoin/bitcoin] Pull request submitted by jtimon

8077 Consensus: Decouple from chainparams.o and timedata.o

Do it for the consensus-critical functions:
• CheckBlockHeader • CheckBlock • ContextualCheckBlockHeader Show more...
github BOT [9:26 PM] [bitcoin:master] 3 new commits by MarcoFalke: fac9349 [qa] Remove hardcoded "4 nodes" from test_framework - MarcoFalke fad68f7 [qa] Reduce node count for some tests - MarcoFalke 8844ef1 Merge #8056: [qa] Remove hardcoded "4 nodes" from test_framework - MarcoFalke
[9:27] [bitcoin/bitcoin] Pull request closed: #8056 [qa] Remove hardcoded "4 nodes" from test_framework by MarcoFalke
github BOT [9:48 PM] [bitcoin/bitcoin] Pull request submitted by petertodd

8078 Disable the mempool P2P command when bloom filters disabled

Only useful to SPV peers, and attackers... like bloom is a DoS vector as far more data is sent than received.
null radix [10:15 PM] joined #commit-activity
github BOT [11:34 PM] [bitcoin:master] 2 new commits by MarcoFalke: fab5233 [qa] test_framework: Set wait-timeout for bitcoind procs - MarcoFalke 37f9a1f Merge #8047: [qa] test_framework: Set wait-timeout for bitcoind procs - MarcoFalke
[11:34] [bitcoin/bitcoin] Pull request closed: #8047 [qa] test_framework: Set wait-timeout for bitcoind procs by MarcoFalke
github BOT [11:48 PM] [bitcoin/bitcoin] Pull request closed: #7826 [Qt] show conflicts of unconfirmed transactions in the UI by jonasschnelli
[11:50] [bitcoin/bitcoin] Pull request re-opened: #7826 [Qt] show conflicts of unconfirmed transactions in the UI by jonasschnelli
----- May 21st ----- Rentaro Matsukata [1:56 AM] joined #commit-activity. Also, @evilone joined, @cryptop joined, @thomas5 joined.
github BOT [1:54 PM] [bitcoin/bitcoin] Pull request submitted by gmaxwell

8080 Do not use mempool for GETDATA for tx accepted after the last mempool req.

The ability to GETDATA a transaction which has not (yet) been relayed is a privacy loss vector.
The use of the mempool for this was added as part of the mempool p2p message and is only needed to fetch transactions returned by it.
github BOT [5:48 PM] [bitcoin/bitcoin] Pull request submitted by gmaxwell

8082 Defer inserting into maprelay until just before relaying.

Also extend the relaypool lifetime by 1 minute (6%) to 16 minutes.
This reduces the rate of not founds by better matching the far end expectations, it also improves privacy by removing the ability to use getdata to probe for a node having a txn before Show more...
Sergey Ukustov [9:17 PM] joined #commit-activity. Also, @stoicism joined.
----- Yesterday May 22nd, 2016 -----
github BOT [5:59 AM] [bitcoin/bitcoin] Pull request submitted by jonasschnelli

8083 Add support for dnsseeds with option to filter by servicebits

Opposite part of https://github.com/sipa/bitcoin-seedepull/36. Including new testnet seed that supports filtering.
Required for SW #7910.
Junseth Sock Puppet Account [6:13 AM] joined #commit-activity
github BOT [1:59 PM] [bitcoin/bitcoin] Pull request submitted by gmaxwell

8084 Add recently accepted blocks and txn to AttemptToEvictConnection.

This protect any not-already-protected peers who were the most recent to relay transactions and blocks to us.
This also takes increases the eviction agressiveness by making it willing to disconnect a netgroup with only one member.
github BOT [5:04 PM] [bitcoin/bitcoin] Pull request submitted by theuni

8085 p2p: Begin encapsulation

This work creates CConnman. The idea is to begin moving data structures and functionality out of globals in net.h and into an instanced class, in order to avoid side-effects in networking code. Eventually, an (internal) api begins to emerge, and as long as the conditions of that api are met, the inner-workings may be a black box.
For now (for ease), a single global CConnman is created. Down the road, the instance could be passed around instead. Also, CConnman should be moved out of net.h/net.cpp, Show more...
github BOT [5:14 PM] [bitcoin/bitcoin] Pull request submitted by sipa

8086 Use SipHash for node eviction

github BOT [5:50 PM] [bitcoin/bitcoin] Pull request closed: #6844 [REST] Add send raw transaction by lclc
----- Today May 23rd, 2016 ----- yannie888 [5:21 AM] joined #commit-activity. Also, @myco joined, @er_sham joined, @ethdealer joined.
github BOT [3:23 PM] [bitcoin/bitcoin] Pull request submitted by pstratem

8087 Introduce CBlockchain and move CheckBlockHeader

[3:23] [bitcoin/bitcoin] Pull request submitted by pstratem

8088 Avoid recalculating vchKeyedNetGroup in eviction logic.

Lazy calculate vchKeyedNetGroup in CNode::GetKeyedNetGroup.
submitted by BillyHodson to Bitcoin [link] [comments]

Any developer (or student) wants an interesting task ? (temporary job for a pay)

The task is: Build a crawler for 4 Satoshi-based coins: namely Bitcoin, Bitcoin Cash, Litecoin and Dash full nodes (not only Masternodes!).

I will pay $1000 in advance and $4000 at completion, once you prove (by past open-source projects), that you're capable of this job. (in Dash, or Bitcoin Cash)
The script needs to be able to crawl Full Nodes of said networks, and built a list of IP addresses, client version, country (GeoIP) and ISP cloud (also GeoIP data), plus uptime. Must be open-source.
You can take this script as a base starting point:
https://github.com/sipa/bitcoin-seeder
-or- this: https://github.com/BitcoinUnlimited/cashnodes
This script requires DNS servers, so you need to make it crawl from a 'localhost', a locally running full node. Independent from DNS.
Result will look like this:
https://ltc.xblau.com/seeds_main.txt
Plus, add GeoIP data.
If you could build a real website with auto-updated statistics, similar to https://bchnodes.online (GeoIP data: Countries + 'ISP clouds' required) for those 4 coins, I would pay extra $10,000. (+open-source code required !)
Reasons:
  1. Today, Dash has no statistics whatsoever on full nodes (only on Masternodes, available here: https://chainz.cryptoid.info/dash/). --- however our network consists not only of Masternodes (whom are limited by amount of coins), but also of Full Nodes, that are unlimited, just like in Bitcoin and Litecoin.
  2. For Bitcoin Cash, I don't fully trust https://bchnodes.online and want to verify their data. (they say 2009 nodes vs. 2240 nodes for https://cash.coin.dance/nodes ... go figure, there's over 10% discrepancy in data statistics.)
  3. For Litecoin network, the node statistics are really poor and incomplete. And it's a multi-billion dollar $ network !
  4. I want to do independent tests for other Satoshi-like coins: Bitcoin, Bitcoin Cash, Litecoin and Dash. (and, shockingly, there is no multi-blockchain crawler, despite the fact that those coins differ ONLY in TCP port number and magic number; they have the same API.)
Disclosure: I'm a Dash Masternode owner, and also a big investor in other coins.
Ping me, and show me your past works, to arrange you a job.
-"Technologov"
submitted by Technologov to dashpay [link] [comments]

Segwit technical discussion

There's a lot of misinformation out there on both sides and I thought it would be nice to have a discussion about segwit.
If you understand it then please share your opinion, but only submit proper arguments. (eg: No comments like "I hate/like segwit because Core created it)
Here's the official introduction:
https://bitcoincore.org/en/2016/01/26/segwit-benefits/
and github:
https://github.com/sipa/bitcoin/tree/segwit
submitted by usrn to btc [link] [comments]

Segregated witness: When and how does it activate or when will this be decided?

Currently BIP141 says
This BIP is to be deployed by version-bits BIP9. Exact details TDB.
From what I can see the reference code still refers to BIP65 and not BIP9.
Is my understanding correct? I'm asking as there are posts which say segwit 'Enters Final Testnet Stage' and am not sure how this could be final without the activation details confirmed.
submitted by redditchampsys to Bitcoin [link] [comments]

Bitcoin core will soon replace the industry standard random number generator with a homebrew script. Sorry for your loss (of entropy)

Instead of any of the libraries on the market sipa and gmaxwell have decided the best thing for bitcoin is to write their own random number generator.
https://github.com/sipa/bitcoin/commit/ce2a03a459cc8bac45c8c8c09ab97ef441bdc089
And you know what they say about random number generation, it's so easy even amature developers can do it! always roll your own crypto functions! never leave that stuff to experts!
submitted by doggheart to Buttcoin [link] [comments]

I want to use a Bitcoin Cash full node crawler for statistics... but how ?

Hello,
One of the ways to crawl the Bitcoin (Cash) network is via 'dnsseed' project.
https://github.com/sipa/bitcoin-seeder
The reason is :
  1. I don't fully trust https://bchnodes.online and want to verify their data. (they say 2009 nodes vs. 2240 nodes for https://cash.coin.dance/nodes ... go figure, there's over 10% discrepancy in data statistics.)
  2. They publish only countries, but not networks (ISPs), where nodes are located.
  3. I want to do independent tests for other Satoshi-like coins: Bitcoin, Bitcoin Cash, Litecoin and Dash. (and, shockingly, there is no multi-coin crawler, despite the fact that those coins differ ONLY in TCP port number and magic number; they have the same API.)
  4. There's this guy "trouble-maker", called BitPico, telling the world, that 49% of all nodes are located in China. Let's prove, or disprove him once and for all. (source: https://www.ccn.com/bitcoin-cash-network-highly-centralized-49-of-all-nodes-run-on-alibabas-facilities-bitpico/)
There is only one problem: I don't have a DNS server, and I can't use it.
Is there an easy way to connect a crawler (bitcoin-seeder, or another ...) to 'localhost', a local Full Node ?
How ?
Thanks,
-"Technologov"
submitted by Technologov to btc [link] [comments]

Segregated witness: When and how does it activate or when will this be decided?

Currently BIP141 says
This BIP is to be deployed by version-bits BIP9. Exact details TDB.
From what I can see the reference code still refers to BIP65 and not BIP9.
Is my understanding correct? I'm asking as there are posts which say segwit 'Enters Final Testnet Stage' and am not sure how this could be final without the activation details confirmed.
submitted by redditchampsys to btc [link] [comments]

[softfork proposal] Strict DER signatures | Pieter Wuille | Jan 21 2015

Pieter Wuille on Jan 21 2015:
Hello everyone,
We've been aware of the risk of depending on OpenSSL for consensus
rules for a while, and were trying to get rid of this as part of BIP
62 (malleability protection), which was however postponed due to
unforeseen complexities. The recent evens (see the thread titled
"OpenSSL 1.0.0p / 1.0.1k incompatible, causes blockchain rejection."
on this mailing list) have made it clear that the problem is very
real, however, and I would prefer to have a fundamental solution for
it sooner rather than later.
I therefore propose a softfork to make non-DER signatures illegal
(they've been non-standard since v0.8.0). A draft BIP text can be
found on:
[https://gist.github.com/sipa/5d12c343746dad376c80](https://gist.github.com/sipa/5d12c343746dad376c80) 
The document includes motivation and specification. In addition, an
implementation (including unit tests derived from the BIP text) can be
found on:
[https://github.com/sipa/bitcoin/commit/bipstrictder](https://github.com/sipa/bitcoin/commit/bipstrictder) 
Comments/criticisms are very welcome, but I'd prefer keeping the
discussion here on the mailinglist (which is more accessible than on
the gist).

Pieter
original: http://lists.linuxfoundation.org/pipermail/bitcoin-dev/2015-January/007156.html
submitted by bitcoin-devlist-bot to bitcoin_devlist [link] [comments]

Segwit integration

I've done some work to get segregated witness working for Joinmarket. Here's a summary of the status of that.
Some highlights of what we need to think about:
Transactions can have mixed segwit/non-segwit inputs and outputs, of course. But that raises:
The obvious issue is about different addresses as markers. The first maker bot to use P2SH addresses stands out and has a trivial marker on his outputs and inputs. And let's say all the makers use P2SH - now we have an even worse problem for takers that don't! The obvious solution is: if you're a taker, and you use P2SH (which could be segwit, or could also just be ordinary multisig) in your wallet, then you respond to swrelorder and swabsorder only; that way, all your inputs and outputs are P2SH. One tiny problem: Joinmarket doesn't yet support P2SH inputs! :)
So effectively, today, it becomes a partitioned joinmarket pit: segwit-enabled taker bots join with segwit-enabled maker bots, and the other non-segwit bots just ignore them. I think that works fine, and quite likely there would be a rapid migration, because segwit will be significantly cheaper. But, lots to think about before that :)
If you'd like to help test, you'll need sipa's segwit branch built and then grab some segnet coins, run my segwit branch of joinmarket above, and use the channel mentioned above on freenode.
Lastly, a note on timing: this is a way off! the PR of segwit into Core is apparently fairly imminent, but we are probably looking at some meaningful amount of time before this is available (and of course, it's not required)
This is just a first effort (although it has "cleared" the issue of the underlying bitcoin code). Thoughts welcome on how to proceed, help even more so.
submitted by waxwing to joinmarket [link] [comments]

How to access SegNet4 testnet raw data structures (raw blocks, raw txs) easily?

Most helpful tool I found so far is BCoin, however it shows everything in deserialized format and no signs from raw transactions with and without witness data/markers etc.
Maybe someone could compile https://github.com/sipa/bitcoin/tree/segwit for windows guy? Thanks.
submitted by johnjacksonbtc to Bitcoin [link] [comments]

Mining centralization pressure from non-uniform propagation speed | Pieter Wuille | Jun 12 2015

Pieter Wuille on Jun 12 2015:
Hello all,
I've created a simulator for Bitcoin mining which goes a bit further than
the one Gavin used for his blog post a while ago. The main difference is
support for links with different latency and bandwidth, because of the
clustered configuration described below. In addition, it supports different
block sizes, takes fees into account, does difficulty adjustments, and
takes processing and mining delays into account. It also simulates longer
periods of time, and averages the result of many simulations running in
parallel until the variance on the result is low enough.
The code is here: https://github.com/sipa/bitcoin-net-simul
The configuration used in the code right now simulates two groups of miners
(one 80%=25%+25%+30%, one 20%=5%+5%+5%+5%), which are well-connected
internally, but are only connected to each other through a slow 2 Mbit/s
link.
Here are some results.
This shows how the group of smaller miners loses around 8% of their
relative income (if they create larger blocks, their loss percentage goes
up slightly further):
Configuration:
Result:
When fees become more important however, and half of a block's income is
due to fees, the effect becomes even stronger (a 15% loss), and the optimal
way to compete for small miners is to create larger blocks as well (smaller
blocks for them result in even less income):
Configuration:
Result:
The simulator is not perfect. It doesn't take into account that multiple
blocks/relays can compete for the same bandwidth, or that nodes cannot
process multiple blocks at once.
The numbers used may be unrealistic, and I don't mean this as a prediction
for real-world events. However, it does very clearly show the effects of
larger blocks on centralization pressure of the system. Note that this also
does not make any assumption of destructive behavior on the network - just
simple profit maximalization.
Lastly, the code may be buggy; I only did some small sanity tests with
simple networks.

Pieter
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submitted by bitcoin-devlist-bot to bitcoin_devlist [link] [comments]

Segwit Upgrade Procedures & Block Extension Data | Peter Todd | Jan 28 2016

Peter Todd on Jan 28 2016:
A few notes on upgrade procedures associated with segregated witnesses:
Initial Deployment

While segregated witnesses is a soft-fork, because it adds new data
blocks that old nodes don't relay segwit nodes can't sync from
non-segwit nodes and still be fully validating; once the segwit softfork
has activated full nodes need witness data to function. This poses a
major problem during deployment: if full node adoption lags miner
adoption, the segwit-supporting P2P network can partition and lose
consensus.
While Pieter Wuille's segwit branch(1) doesn't yet implement a fix for
the above problem, the obvious thing to do is to add a new service bit
such as NODE_SEGWIT, and/or bump the protocol version, and for outgoing
peers only connect to peers with segwit support. Interestingly, a
closely related problem already exists in Bitcoin Core: neither addrman
nor the outgoing connection thread takes what service bits a peer
advertises into account. So if a large number of non-block-relaying
nodes joined the network and advertised their addresses the network
could, in theory, partition even without an explicit attack. (My own
full-RBF fork of Bitcoin Core does fix(2) this issue, though by
accident!)
Note how because of this the segwit soft-fork has properties not unlike
hard-forks in terms of the need for nodes to upgrade with regard to the
P2P layer. Even with the above fix, the worst case would be for segwit
to not be adopted widely by full node operators, resulting in a network
much more vulnerable to attacks such as DoSing nodes. This is one of the
(many) reasons why hard-forks are generally significantly more dangerous
than soft-forks.
Future Upgrades

Segwit isn't going to be the last thing that adds new block data. For
example, my own prev-block-proof proposal(3) requires that blocks commit
to another tree, which itself is calculated using a nonce that must be
passed along with the block data. (U)TXO commitments are another
possible future example.
BIP141 (currently) suggests an Extensible Commitment Structure(4)
consisting of a hashed linked list of consensus-critical commitments,
with a redefinable nonce at the end of the list for future soft-forks.
Currently this nonce is put into the otherwise useless, and non-hashed,
witness for the coinbase transaction(6) and a block is invalid if its
witness contains more than that single nonce.(7)
Unfortunately, this means that the next soft-fork upgrade to add
additional data will have the above relaying problem all over again!
Even a minimal upgrade adding a new commitment - like my
prev-block-proof proposal - needs to at least add another nonce for
future upgrades. In addition to having to upgrade full nodes, this also
requires systems like the relay network to upgrade, even though they may
not themselves otherwise need to care about the contents of blocks.
A more subtle implication of this problem is how do you handle parallel
upgrades, as proposed by BIP9? Splitting the P2P network into
non-upgraded nodes, and a much smaller group of upgraded nodes, is bad
enough when done every once in a awhile. How does this look with more
frequent upgrades, not necessarily done by teams that are working
closely with each other?
Proposal: Unvalidated Block Extension Data

1) Remove the restriction that the coinbase witness contain exactly one
32byte value.
2) Hash the contents of the coinbase witness (e.g. as a merkle tree) and
commit them in place of the current nonce commitment.
3) Include that data in the blocksize limit (to prevent abuse).
Now future soft-forks can simply add additional data, which non-upgraded
nodes simply see as extension data that they don't know how to fully
validate. All nodes can however validate that data came from the miner,
and thus they can freely propagate that data without risk of attack
(Bitcoin Core used to allow additional data to be included with
transactions, which was used in a DoS attack (CVE-2013-4627)).
This is more efficient than it may appear at first glace. As most future
upgrades are expected to be additional commitments where full nodes can
deterministically recalculate the commitment, the additional data for
each new commitment is just 32 bytes.
A significant design consideration is that if arbitrary data can be
added, it is very likely that miners will make use of that ability for
non-Bitcoin purposes; we've already run into problems deploying segwit
itself because of pools using the coinbase space for advertising and
merge-mining. Avoiding this problem is easiest with a merkelized
key:value mapping, with the ability to use collision-resistant ID's as
keys (e.g. UUID).
Secondly, does using the coinbase witness for this really make sense?
Logically it'd make more sense to change the way blocks are serialized,
much the same way transaction serialization was changed to accomodate
segwit; stuffing this in the coinbase witness smells like a hack. (along
those lines, note how witnesses themselves could have been implemented
this way - probably too late to change now)
References

1) https://github.com/sipa/bitcoin/tree/segwit
2) https://github.com/petertodd/bitcoin/blob/replace-by-fee-v0.12.0rc2/src/net.cpp#L1616
3) http://lists.linuxfoundation.org/pipermail/bitcoin-dev/2015-Decembe012103.html
5) https://github.com/bitcoin/bips/blob/6a315c023f13d83c58aab98cf8668d74cf7566c7/bip-0141.mediawiki#Extensible_commitment_structure
6) https://github.com/sipa/bitcoin/blob/37973bf2efd7a558c86bf35455a1355e5b0d5d64/src/main.cpp#L3212
7) https://github.com/sipa/bitcoin/blob/37973bf2efd7a558c86bf35455a1355e5b0d5d64/src/main.cpp#L3209

https://petertodd.org 'peter'[:-1]@petertodd.org
0000000000000000003b293f5507f7787f1ba64ba58a21c46ba4454c21a88710
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SegWit testnet is live | Eric Lombrozo | Jan 07 2016

Eric Lombrozo on Jan 07 2016:
I am pleased to report that as of December 31, 2015 we have been successfully running a segregated witness testnet, called segnet, and have already implemented rudimentary wallets with support.
For source code, please look at sipa's github repo:
https://github.com/sipa/bitcoin/tree/segwit
And some example signing code at my repo:
https://github.com/CodeShark/BitcoinScriptExperiments/blob/mastesrc/signwitnesstx.cpp
Several wallets have already committed to supporting it including mSIGNA, GreenAddress, GreenBits, Blocktrail, and NBitcoin. More wallets are expected to be added to this list soon. If you're a wallet dev and are interested in developing and testing on segnet please contact me.
We're right on schedule and are very excited about the fundamental improvements to bitcoin that segwit will enable.
Eric
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Segnet4 | Eric Lombrozo | Mar 30 2016

Eric Lombrozo on Mar 30 2016:
Hello everyone.
Pieter Wuille has pushed code for a new segwit testnet that features activation via BIP9 as well as support for BIP68, BIP112, and BIP113. In particular, it now supports Lightning Network app development and collaboration.
I encourage everyone to spin up a node and try it out.
For source code, please go to Pieter's github repo:
https://github.com/sipa/bitcoin/tree/segwit4 https://github.com/sipa/bitcoin/tree/segwit4
Feedback is welcome here or on the #segwit-dev channel on Freenode.
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Bitcoin.sipa.be is broken, any alternatives?

Bitcoin.sipa.be is broken, any alternatives? submitted by staledumpling to Bitcoin [link] [comments]

fight on github - /u/deadalnix (infamous bitcoinABC lead devel, known for stealing credits of Sipa's Schnorr-signatures) now does same for security fixes in Bitcoin Core

fight on github - deadalnix (infamous bitcoinABC lead devel, known for stealing credits of Sipa's Schnorr-signatures) now does same for security fixes in Bitcoin Core submitted by metalzip to Bitcoin [link] [comments]

Segregated witness by sipa · Pull Request #7910 · bitcoin/bitcoin - SegWit Pull Request for Bitcoin Master Branch. Pieter Wuille is a machine.

Segregated witness by sipa · Pull Request #7910 · bitcoin/bitcoin - SegWit Pull Request for Bitcoin Master Branch. Pieter Wuille is a machine. submitted by Lejitz to Bitcoin [link] [comments]

sipa to luke-jr on #bitcoin-core-dev : " i think you're insane " -- and later : " apologies for the ad hominem... but i believe your argument it nonsense "

refreshing to see luke-jr called out even by core for the toxic idiot he is .
submitted by realistbtc to btc [link] [comments]

/u/deadalnix (infamous bitcoinABC lead devel, known for stealing credits of Sipa's Schnorr-signatures) now does same for security fixes in Bitcoin Core

deadalnix (infamous bitcoinABC lead devel, known for stealing credits of Sipa's Schnorr-signatures) now does same for security fixes in Bitcoin Core submitted by fakecoins to btc [link] [comments]

Pieter Wuille (/u/sipa) never held a job before working at Blockstream. What makes him qualified to have any influence over how Bitcoin works?

submitted by RottenToTheBSCore to btc [link] [comments]

09-12 09:52 - 'Upthread of that exchange are these nuggets: / [quote] -Sipa, July 2nd / [quote] -Chjj, in response to Greg / [quote] -Greg / FWIW, I personally think if your node crashes from a few hundred megs of mem usage, you should buy a new...' by /u/324JL removed from /r/Bitcoin within 0-8min

'''
Upthread of that exchange are these nuggets:
I was aware that it was possible to make the coin cache fetch at least several 100 MB into memory, and pertxout was a generic improvement over that as it reduces the difference between the average case and the worst case. I did not know that the potential effect of such a UTXO-fetching attack was so large however, so thank you for investigating.
-Sipa, July 2nd
Bcoin originally used its own pertxout impl in early 2016 (check the git history), long before Core had even considered it. The data management had switched back and forth a number of times. It was a mistake to think the core devs even knew what the hell they were doing when I was porting some of that spaghetti code of vector-based UTXOs. I switched it back because I had never actually benchmarked it in the old days vs vector-based utxos. Secondly, you claim you knew about this for a long time? And what? You just put it on the backburner for how many months, years? Smells off to me.
-Chjj, in response to Greg
Apparently sipa thought the worst case was only a few hundred megs, which itself would have been considered a serious vulnerability
-Greg
FWIW, I personally think if your node crashes from a few hundred megs of mem usage, you should buy a new computer, because if you have less than a Gigabyte of memory, your computer is over 15 years old. Which is why Sipa probably wasn't concerned.
'''
Context Link
Go1dfish undelete link
unreddit undelete link
Author: 324JL
submitted by removalbot to removalbot [link] [comments]

Bitcoin Price Correction Targets, Incoming Solar Wind  Cc BMR 20170516 BITCOIN LIVE : Weekend BREAKOUT! LTC ETH ADA Ep.1003 ... All About Segregated Witness Activation How will we get to 21 Million bitcoins? Is Bitcoin a Bubble? - YouTube

Bitcoin network graphs. hash rate; block version; Click on the graphs to see larger versions. Total network hashing rate. Linear axis: Exponential axis: Total cumulative number of hashes. Daily growth rate. Proof of Work Equivalent Days. The ratio of total work divided by estimate of hashrate at that time. Thus it's the amount of time it would take for an attacker with 100% of the hashrate to ... bitcoin.sipa.be Server iP: Current resolution: domain resolution record: 2019-08-14-----2020-10-26 144.217.240.89. 2018-02-26-----2018-02-27 45.32.130.19 Refactors (sipa/[email protected]) [+50 -39]: 107b57d scripted-diff: put ECDSA in name of signature functions: In preparation for adding Schnorr versions of CheckSig, VerifySignature, and ComputeEntry, give them an ECDSA specific name. 8bd2b4e refactor: rename scriptPubKey in VerifyWitnessProgram to exec_script: The old name is confusing, as it doesn't store a scriptPubKey, but the ... Miniscript is a language for writing (a subset of) Bitcoin Scripts in a structured way, enabling analysis, composition, generic signing and more.. Bitcoin Script is an unusual stack-based language with many edge cases, designed for implementing spending conditions consisting of various combinations of signatures, hash locks, and time locks. May 30, 2016 sipa commented on pull request sipa/bitcoin#87 Including in next batch. Post Views: 142. This entry was posted in Bitcoin News on May 30, 2016 by adminbtc. Post navig

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Bitcoin Price Correction Targets, Incoming Solar Wind Cc BMR 20170516

Lecture by Nathaniel Popper, New York Times reporter and author of the recent book Digital Gold. Comments by Guillermo Calvo, Professor of Economics and International and Public Affairs and ... Is Bitcoin a Bubble? https://www.facebook.com/groups/420592348344123/ © Alain Pitton—Sipa USA via AP Bitcoin prices hit $19,000 early Monday morning, as Bitc... Ich habe mich als studierter Diplom-Mathematiker am bayrischen Mathematik-Abitur 2019 versucht – und bin gescheitert. Die Aufgaben sind absurd schwierig, ein... At Crypto Hustlers we cover everything you need to know to be successful and make money in the Crypto currency space. Bitcoin is just the beginning of a whol... Lors de ce meetup du 16 octobre 2019, nous accueillons Sosthène à Neuchatêl pour une présentation de Miniscript. Sources : Bitcoin Optech Newsletter #61 : ht...

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