Joining is easy.
Subscribe to our announce list. We'll send you a confirmation email in reply. Come back, enter the confirmation password, and you're done!
You're perhaps aware of Google Translation services, and if you know more than one human language you can contribute and help to improve this service via Google Translate Community (BETA).
You also might be interested to know that Yandex, a Russian google, has their Yandex Translation Service running, which in many cases gives better translation for Russian - English pair of languages.
“How’d you solve the icing problem?”
“Icing problem?”
“Might want to look into it.”
— Iron Man (2008)
On a particularly cold Saturday morning a couple of years ago, my mobile phone couldn’t get any signal for a few hours. But I didn’t really care, because I had breakfast to eat, animals to feed, and nobody I urgently needed to talk to at the time. Also it came good again shortly after midday.
The following week the same thing happened, but for rather longer, i.e. well into the evening. This was enough to prompt me to use my landline to call Optus (our mobile phone provider) and report a fault. The usual dance ensued:
“Have you tried turning it off and on again?”
“Yes.”
“Have you tried a different handset?”
“Yes.”
“A different SIM?”
“Yes.”
“Holding the phone in your other hand?”
“Yes.”
“Sacrificing a lamb to the god Mercury?”
“Yes.”
I might be misremembering the details of the conversation, but you get the idea. Long story short, I got a fault lodged.
Later I received a call – on my mobile – asking if my mobile was working again. “Indeed it is, and you wouldn’t have been able to make this call if it wasn’t”, I replied. Then I asked what the problem had been. “Let me check”, said the support person. “Uhm… It says here there was… 100mm of ice on the local tower.”
Flash forwards to a couple of days ago, when snow fell down to sea level for the first time since 2005, and my mobile phone was dead again. I can only assume they haven’t solved the icing problem, and that maybe the local NBN fixed wireless tower suffers from the same affliction, as that was dead too for something like 24 hours.
It was very pretty though.
There’s a significant debate going on at the moment in the Bitcoin world; there’s a great deal of information and misinformation, and it’s hard to find a cogent summary in one place. This post is my attempt, though I already know that it will cause me even more trouble than that time I foolishly entitled a post “If you didn’t run code written by assholes, your machine wouldn’t boot”.
The Technical Background: 1MB Block LimitThe bitcoin protocol is powered by miners, who gather transactions into blocks, producing a block every 10 minutes (but it varies a lot). They get a 25 bitcoin subsidy for this, plus whatever fees are paid by those transactions. This subsidy halves every 4 years: in about 12 months it will drop to 12.5.
Full nodes on the network check transactions and blocks, and relay them to others. There are also lightweight nodes which simply listen for transactions which affect them, and trust that blocks from miners are generally OK.
A normal transaction is 250 bytes, and there’s a hard-coded 1 megabyte limit on the block size. This limit was introduced years ago as a quick way of avoiding a miner flooding the young network, though the original code could only produce 200kb blocks, and the default reference code still defaults to a 750kb limit.
In the last few months there have been increasing runs of full blocks, causing backlogs for a few hours. More recently, someone deliberately flooded the network with normal-fee transactions for several days; any transactions paying less fees than those had to wait for hours to be processed.
There are 5 people who have commit access to the bitcoin reference implementation (aka. “bitcoin-core”), and they vary significantly in their concerns on the issue.
The Bitcoin Users’ PerspectiveFrom the bitcoin users perspective, blocks should be infinite, and fees zero or minimal. This is the basic position of respected (but non-bitcoin-core) developer Mike Hearn, and has support from bitcoin-core ex-lead Gavin Andresen. They work on the wallet and end-user side of bitcoin, and they see the issue as the most urgent. In an excellent post arguing why growth is so important, Mike raises the following points, which I’ve paraphrased:
At this point, it’s worth mentioning another bitcoin-core developer: Jeff Garzik. He believes that the bitcoin userbase has been promised that transactions will continue to be almost free. When a request to change the default mining limit from 750kb to 1M was closed by the bitcoin lead developer Wladimir van der Laan as unimportant, Jeff saw this as a symbolic moment:
Disappointing. New #Bitcoin Core policy: stealth fee increases https://t.co/pir9uUOLet Zero plan to communicate this to BTC users :(
— Jeff Garzik (@jgarzik) July 21, 2015
What Happens If We Don’t Increase Soon?Mike Hearn has a fairly apocalyptic view of what would happen if blocks fill. That was certainly looking likely when the post was written, but due to episodes where the blocks were full for days, wallet designers are (finally) starting to estimate fees for timely processing (miners process larger fee transactions first). Some wallets and services didn’t even have a way to change the setting, leaving users stranded during high-volume events.
It now seems that the bursts of full blocks will arrive with increasing frequency; proposals are fairly mature now to allow users to post-increase fees if required, which (if all goes well) could make for a fairly smooth transition from the current “fees are tiny and optional” mode of operation to a “there will be a small fee”.
But even if this rosy scenario is true, this begs the question of how high fees can become before bitcoin becomes useless. 1c? 5c? 20c? $1?
So What Are The Problems With Increasing The Blocksize?In a word, the problem is miners. As mining has transitioned from a geek pastime, semi-hobbyist, then to large operations with cheap access to power, it has become more concentrated.
The only difference between bitcoin and previous cryptocurrencies is that instead of a centralized “broker” to ensure honesty, bitcoin uses an open competition of miners. Given bitcoin’s endurance, it’s fair to count this a vital property of bitcoin. Mining centralization is the long-term concern of another bitcoin-core developer (and my coworker at Blockstream), Gregory Maxwell.
Control over half the block-producing power and you control who can use bitcoin and cheat anyone not using a full node themselves. Control over 2/3, and you can force a rule change on the rest of the network by stalling it until enough people give in. Central control is also a single point to shut the network down; that lets others apply legal or extra-legal pressure to restrict the network.
What Drives Centralization?Bitcoin mining is more efficient at scale. That was to be expected[7]. However, the concentration has come much faster than expected because of the invention of mining pools. These pools tell miners what to mine, in return for a small (or in some cases, zero) share of profits. It saves setup costs, they’re easy to use, and miners get more regular payouts. This has caused bitcoin to reel from one centralization crisis to another over the last few years; the decline in full nodes has been precipitous by some measures[5] and continues to decline[6].
Consider the plight of a miner whose network is further away from most other miners. They find out about new blocks later, and their blocks get built on later. Both these effects cause them to create blocks which the network ignores, called orphans. Some orphans are the inevitable consequence of miners racing for the same prize, but the orphan problem is not symmetrical. Being well connected to the other miners helps, but there’s a second effect: if you discover the previous block, you’ve a head-start on the next one. This means a pool which has 20% of the hashing power doesn’t have to worry about delays at all 20% of the time.
If the orphan rate is very low (say, 0.1%), the effect can be ignored. But as it climbs, the pressure to join a pool (the largest pool) becomes economically irresistible, until only one pool remains.
Larger Blocks Are Driving Up Orphan RatesLarge blocks take longer to propagate, increasing the rate of orphans. This has been happening as blocks increase. Blocks with no transactions at all are smallest, and so propagate fastest: they still get a 25 bitcoin subsidy, though they don’t help bitcoin users much.
Many people assumed that miners wouldn’t overly centralize, lest they cause a clear decentralization failure and drive the bitcoin price into the ground. That assumption has proven weak in the face of climbing orphan rates.
And miners have been behaving very badly. Mining pools orchestrate attacks on each other with surprising regularity; DDOS and block withholding attacks are both well documented[1][2]. A large mining pool used their power to double spend and steal thousands of bitcoin from a gambling service[3]. When it was noticed, they blamed a rogue employee. No money was returned, nor any legal action taken. It was hoped that miners would leave for another pool as they approached majority share, but that didn’t happen.
If large blocks can be used as a weapon by larger miners against small ones[8], it’s expected that they will be.
More recently (and quite by accident) it was discovered that over half the mining power aren’t verifying transactions in blocks they build upon[4]. They did this in order to reduce orphans, and one large pool is still doing so. This is a problem because lightweight bitcoin clients work by assuming anything in the longest chain of blocks is good; this was how the original bitcoin paper anticipated that most users would interact with the system.
The Third Side Of The Debate: Long Term Network FundingBefore I summarize, it’s worth mentioning the debate beyond the current debate: long term network support. The minting of new coins decreases with time; the plan of record (as suggested in the original paper) is that total transaction fees will rise to replace the current mining subsidy. The schedule of this is unknown and generally this transition has not happened: free transactions still work.
The block subsidy as I write this is about $7000. If nothing else changes, miners would want $3500 in fees in 12 months when the block subsidy halves, or about $2 per transaction. That won’t happen; miners will simply lose half their income. (Perhaps eventually they form a cartel to enforce a minimum fee, causing another centralization crisis? I don’t know.)
It’s natural for users to try to defer the transition as long as possible, and the practice in bitcoin-core has been to aggressively reduce the default fees as the bitcoin price rises. Core developers Gregory Maxwell and Pieter Wuille feel that signal was a mistake; that fees will have to rise eventually and users should not be lulled into thinking otherwise.
Mike Hearn in particular has been holding out the promise that it may not be necessary. On this he is not widely supported: that some users would offer to pay more so other users can continue to pay less.
It’s worth noting that some bitcoin businesses rely on the current very low fees and don’t want to change; I suspect this adds bitterness and vitriol to many online debates.
SummaryThe bitcoin-core developers who deal with users most feel that bitcoin needs to expand quickly or die, that letting fees emerge now will kill expansion, and that the infrastructure will improve over time if it has to.
Other bitcoin-core developers feel that bitcoin’s infrastructure is dangerously creaking, that fees need to emerge anyway, and that if there is a real emergency a blocksize change could be rolled out within a few weeks.
At least until this is resolved, don’t count on future bitcoin fees being insignificant, nor promise others that bitcoin has “free transactions”.
[1] http://www.coindesk.com/bitcoin-mining-pools-ddos-attacks/ “Bitcoin Mining Pools Targeted in Wave of DDOS Attacks” Coinbase 2015
[2] http://blog.bettercrypto.com/?p=1131 “Block Withholding Attacks – Recent Research” N T Courtois 2014
[3] https://bitcointalk.org/index.php?topic=327767.0 “GHash.IO and double-spending against BetCoin Dice” mmtech et. al 2013
[4] https://www.reddit.com/r/Bitcoin/comments/3c8tq2/questions_about_the_july_4th_bip66_fork/cstgajp “Questions about the July 4th BIP66 fork”
[5] https://twitter.com/petertoddbtc/status/608475414449778688 “350,000 full nodes to 6,000 in two years…” P Todd 2015
[6] https://getaddr.bitnodes.io/dashboard/?days=365 “Reachable nodes during the last 365 days.” Bitnodes.io
[7] https://bitcointalk.org/index.php?topic=532.msg6306#msg6306 “Re: Scalability and transaction rate” Satoshi 2010
[8] http://www.mail-archive.com/bitcoin-development@lists.sourceforge.net/msg08161.html “[Bitcoin-development] Mining centralization pressure from non-uniform propagation speed” Pieter Wuille 2015
My good friends at the Amateur Radio Experimenters Group (AREG), an Adelaide based Ham radio club, have organised a special FreeDV QSO Party Weekend on Sat/Sun September 12/13th. This is a great chance to try out FreeDV, work VK5 using open source HF digital voice, and even talk to me!
All the details including paths, frequencies, and times over on the AREG site.
This is the entire complaint that was received:
We are an IT security company from Spain.
We have detected sensitive information belonging to Banesco Banco Universal, C.A. clientes.
As authorized representative in the resolution of IT security incidents affecting Banesco Banco Universal, C.A., we demand the deletion of the content related to Banesco Banco Universal, C.A, clients. This content violates the law about electronic crime in Venezuela (see “Ley Especial sobre Delitos Informáticos de Venezuela”, Chapter III, Articles 20 y 23).
Note the complete lack of any information regarding what URLs, or even which site(s), they consider to be problematic. Nope, just “delete all our stuff!” and a wave of the “against the law somewhere!” stick.
Carina gave a fantastic talk of the very real consequences of our interactions with data mining and the algorithms used to target us. A must watch when the video comes out.
Update: Video is now available here. Slides are over there.
Adventures in pip landA humorous and contructive talk on the pitfalls of pip. Strongly recommended that people no longer use it.
Arrested Development - surviving the awkward adolescence of a microservices-based applicationby Katie Bell
by Tom Eastman
We’ve finally had time to finalise Korora 22 and images are now available. I strongly recommend downloading with BitTorrent if you can.
We are not shipping Adobe Flash by default from 22 onwards, due to consistent security flaws. We still include the repository however, so users can install via the package manager or command line if they really want it:
sudo dnf install flash-plugin
Alternatively, install Google Chrome which includes the latest version of Flash.
Also, KDE 4 is not available for this release, so if you are not ready to move to KDE 5, then please stick to Korora 21.
The list of available wifi channels is slightly different from country to country. To ensure access to the right channels and transmit power settings, one needs to set the right regulatory domain in the wifi stack.
LinuxFor most Linux-based computers, you can look and change the current regulatory domain using these commands:
iw reg get iw reg set CAwhere CA is the two-letter country code when the device is located.
On Debian and Ubuntu, you can make this setting permanent by putting the country code in /etc/default/crda.
Finally, to see the list of channels that are available in the current config, use:
iwlist wlan0 frequency OpenWRTOn OpenWRT-based routers (including derivatives like Gargoyle), looking and setting the regulatory domain temporarily works the same way (i.e. the iw commands above).
In order to persist your changes though, you need to use the uci command:
uci set wireless.radio0.country=CA uci set wireless.radio1.country=CA uci commit wirelesswhere wireless.radio0 and wireless.radio1 are the wireless devices specific to your router. You can look them up using:
uci show wirelessTo test that it worked, simply reboot the router and then look at the selected regulatory domain:
iw reg get Scanning the local wifi environmentOnce your devices are set to the right country, you should scan the local environment to pick the least congested wifi channel. You can use the Kismet spectools (free software) if you have the hardware, otherwise WifiAnalyzer (proprietary) is a good choice on Android (remember to manually set the available channels in the settings).
Excellent keynote on using Python in education. Many interesting insights into what's being done well, what needs improving and how to contribute.
Slow Down, Compose Yourself - How Composition Can Help You Write Modular, Testable Codeby Todd Owen (http://2015.pycon-au.org/schedule/30057/view_talk?day=saturday)
by Tim Butler
by Victor Palma
by Monty Taylor
What Monty Wants
inaugust.com/talks/a-vision-for-the-future.html
The Future of Identity (Keystone) in OpenStackby Jamie Lennox
by Angus Lees
by Monty Taylor