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James Purser: A letter sent, a disappointment received.

46 min 23 sec ago

While I was distracted from the whole blogging thing, something did actually get me hacking at the keyboard on something that wasn't code. That was the metadata laws and the actions of the Labor party in allowing them to pass through with a few amendments that in the long run are going to be meaningless.

So I hacked out an email to my local federal member Stephen Jones (which I've included below).

I didn't actually receive a response from Stephen Jones until after the legislation passed through the Senate, and I have to say that I was seriously disappointed. I don't expect a lot from my representatives, but what I would like is something that actually addresses the points that I set out in the original email. What I got was the stock standard "we need to do this because [INSERT SOMETHING ABOUT TERRISMS HERE]".

Sigh.

Dear Stephen Jones,

I've always found you to be a decent person and someone who cares for his electorate. However I am deeply concerned at the fact that you and Labor seem to have allowed the governments Data Retention Legislation to pass without either looking at the amendments or in fact seriously considering whether it is needed at all.

Leaving aside the near Orwellian prospect of the entire nations communications being tracked for a rolling period of two years. There are a huge number of problems that seem to have been overlooked in the name of "national security".

- No warrants. There is no judicial oversight of the access to this data. I cannot believe that this is a thing that is supported. Why do we now think that it's not possible for police and other services to misuse their powers? Checks and balances exist for a reason and any move to water them down is dangerous.

- The actual data to be retained still has not been defined. In fact the legislation with amendments requires the ISP's to determine what "type" of communication it is, which means that the ISP will need to look at the content of the packet. This is not just "envelope" stuff, this is looking inside the envelope and working out what the letter you're mailing is about. This is bad.

- There doesn't appear to actually be a need for it. What problem does it solve that hasn't already been solved? The police and intelligence services seem to be operating quite well already, arresting those who would do us harm and relying on targetted communicates intercepts.

- The possibilities for abuse are through the roof. Not only for official abuse but you've just created a massive honeypot for every script kiddie and cracker around.

- What safeguards are there against using this information retrospectively? Say a new government comes into power and decides that something should be illegal and it should be illegal retrospectively? What's to stop them using this great store of data to start prosecuting people?

Labor and the government have both just told the Australian public that they are now suspect. That their every action needs to be tracked, just in case they may do something wrong. This is not something I am comfortable with, and frankly neither should you be.

 

Blog Catagories: Politics

James Purser: Dare Devil

Thu, 2015-04-16 23:30

So we've been watching Dare Devil over the last couple of nights, we're up to episode 3 and I have to say I'm really impressed.

I've never been a big fan of Dare Devil the character, and dear god the movie was complete shite (up there with the first Hulk movie featuring Eric Bana for badness), but this series has really sucked me in.

For episode 3 what really brought it home for me was Ben Urich. A journalist for the Daily Bugle in the comics, Urich represents the every man and is often used to tell the story of the normal people caught up in the semi regular destruction rained down upon New York (which has included the Hulk taking over, everyone in Manhatten being turned into Spider creatures, the almost annual flooding by Namor and of course an alien invasion or two).

I'm really liking the shorter series formats for the Marvel shows as well (well leaving aside Agents of Shield). They carry the comic book story arc feel much better than trying to drag things out for 23 episodes. Agent Carter proved that and now so is Dare Devil.

All in I'm pretty happy with the state of Marvels Cinematic Universe, and am looking forward to seeing the next tranche.

Blog Catagories: mediamarvel

Leon Brooks

Tue, 2015-04-14 21:05
Imagine a roadblock which is a wall of perfectly transparent AeroGel.



Here you are, barrelling down a highway at the speed limit, when suddenly you realise that you have come to a halt, so gently that you weren’t aware of as much as having slowed down.



Viola! You now have some idea of what is like to have been Gaslighted for over 5000 days by a person who is an emotional vampire: their goal is not to kill you, it’s to keep sucking away your self in order to present a façade of having a self themselves.



If you have been “told,” tens of thousands of times in indirect ways (never directly: you only become aware of an increasing number of knives accumulating in your back over a span of time), that you cannot succeed, that establishes just such an emotional roadblock.



Right now, teaching a Raspberry Pi to sing is not happening. I know what needs to be done. The resources to discover exactly how to do it are freely available. It simply does not happen. Welcome to the AeroGel roadblock.



The self-righteous Psychopath who spent so much time installing this roadblock in my mind can do no wrong in their own eyes. To actually imply that their integrity is less than complete inspires a rage attack (which is not the same as anger: there is no control at all). Deprogramming each of these blocks will not take place instantly.

Tim Serong: Get off my Lawn

Tue, 2015-04-14 02:28

When I was about the right age to first think that taking compromising photos of myself might be good for a lark, technology was a little different. Mobile phones that weren’t actually bricks anymore could show maybe two lines of pixelated text on an unpleasantly glowing background, terrible quality digital cameras were barely affordable, and connecting to the internet actually had a sound – kind of like KSShhh-aaa-KWEO-pung-pung-drhdrhdrhd-KHH, but it went for longer than that. Or maybe it was: mobile phones only existed in gangster movies where they were installed as part of a car, digital cameras didn’t exist, and I only had access to a few local BBSes. I forget the specifics, but that’s not the point – the point is that when I was in my teens, technology was shit, and nobody had any of it. Now, technology is excellent, everybody has all of it, it’s really easy to use, and the ways in which we interact with our technology shape the ways we expect our technology to work.

If I write an email to someone, I’m thinking “I will type my message in this box here, hit SEND, and then they will receive the message and read it”. I am not thinking “I will type my message in here, hit SEND, then it will be transmitted in plain text across a vast network of computer systems, through a number of mail servers, possibly be recorded by several government agencies in case I’m a terrorist, be stored for a little while in a mail spool and possibly backed up by some ISP, before eventually being downloaded and read by the intended recipient”.

Same with photos: “I will take a picture and share it with my wife” is a distinctly personal experience (regardless of what it’s a photo of), and that’s what I’m thinking at the time. I am not thinking “I will take a picture with my phone which will then be uploaded across that same vast network to a cloud system somewhere and stored for Eris-only-knows how long in some other jurisdiction which can probably be hacked by script kiddies”.

Technology now is all about communicating with people, and about sharing our experiences, and that we can do this without having any idea what’s actually going on is fantastic. The price though is that with each service we use, we give up a certain amount of privacy, and what privacy we give up is not necessarily obvious.

To go back to the compromising photo example: When all I had was a little film camera, nobody I knew ever took photos they wouldn’t be happy for random strangers to see, because we all knew that we had to take the film to get processed – the mechanics of how the technology worked were at least somewhat obvious to the people using the technology. As far as I am aware, there are no nude photos in existence of my teenage self and partners, because we didn’t want those perverts in the photo shop to see them.

I want a world where user experience accurately reflects potential privacy – not “sharing to circles”, or allegedly private “private messages”, but where any share that could conceivably result in non-private communication is preceded by a dialog that states “I hope you know that this will go down on your permanent record”. Because privacy is important – as Bruce Schneier said: “Privacy is not about something to hide. Privacy is about human dignity. Privacy is about individuality. Privacy is about being able to decide when and how we show ourselves to other people.”

Dave Hall: Managing Variables in Drupal 7

Mon, 2015-04-13 23:30

A couple of times recently the issue of managing variables in Drupal 7 has come up in conversation with other developers. This post outlines the various ways of managing variables in Drupal sites. The three things this guide ensures:

  • Sensitive data is kept secure
  • Variables are correct in each environment
  • You are able to track your variables (and when they changed)
The Variables Table

The most common place you'll find configuration variables is in Drupal's variable table (aka {variable}). The values in this table are often managed via admin forms that use system_settings_form(). Users enter the values click "Save configuration" and the data is stored in the database.

If you prefer to manage your configuration via the command line and know the variable you wish to set you can use drush vset. This does exactly the same thing as admin form, without needing to click on a mouse.

$conf Array

While the variables table is great at storing our variables, there are times when you want to enforce a setting. This might be because you want to prevent users from changing it (accidentally or otherwise) or because you need it to be different in each environment. The $conf array in settings.php always overrides any values in the variable table.

Acquia, Pantheon and platform.sh all provide environment variables so you can use different values in your $conf array depending on the environment.

Exporting Variables

In Drupal 7, the common way to export your variables is by using Strongarm with Features. I'm not going to cover how to do this as there is loads of documentation already available on this topic.

If your variable changes on a per environment basis or if it calculated on the fly, then you won't want to use strongarm+features as the exported values are static. You will need to put them in settings.php.

Note to self: I should debug and reroll my patch for adding support in alter hooks strongarm.

My settings.php is Out of Control!

This is a common problem, especially on more complex sites. To avoid this I recommend creating sites/default/settings/settings.[env].php files. Your settings.php file should check for the environment in an environment variable and then include the appropriate settings.[env].php file.

What About Sensitive Data?

You can encrypt variables on a case by case basis using the encrypt module and some custom code similar to what I recently implemented in the Acquia SDK module (see on store and on read examples). Warning: This doesn't encrypt the data if you're using drush vset.

If you are storing sensitive data in your variables table I would recommend you implement hook_sql_sync_sanitize() which will delete the sensitive data from your db when drush sql-sanitize or drush sql-sync --sanitize are run.

How to Decide?

This little code snippet should help you decide.

<?php // Don't try using this code in your Drupal site. if (!using_version_control()) { // Seriously there is no point in doing this without version control. abandon_all_hope(); drupal_exit(); } if (is_data_sensitive($var)) { $var = encrypt_var($var); if (!we_use_drush_based_workflows()) { learn_and_implement_drush_based_workflows(); // I'm serious! } } implement_hook_sql_sync_sanitize($var); } if (is_unique_per_environment($var)) { store_conf_array($var); } else { store_in_db($var); if (!we_use_features_based_workflow()) { learn_and_implement_features_based_worflows(); // I'm serious! } export_using_strongarm($var); }

Leon Brooks

Mon, 2015-04-13 19:27
Would a book entitled “I married a Psychopath” or the like sell well?



One of the risks here for even a strong Empath is that there are no “red flags” in the differences between feelings and expression of them (body-language etc), for the very simple reason that there are no feelings, so there are no differences to sense.



It must be a lonely, empty life for someone who consists only of an empty bubble of Ego. Yet they are the only person who could change that. It begins with genuine humility (which has nothing to do with acting humble). They need to think nothing of themselves.



This may not sound so difficult until you understand that they think everything of themselves, full time. Religion (including Atheism) is not possible for them, as the only person they worship is themselves.





Sridhar Dhanapalan: Twitter posts: 2015-04-06 to 2015-04-12

Mon, 2015-04-13 00:27

Tim Serong: Pigs and Bread

Sun, 2015-04-12 23:27

In farming related news, we have pigs again, and I’ve finally written up my bread recipe on our new blog at downsouthfarm.com. My random commentary about food and farming related matters will henceforth be posted there, while everything else I usually rattle on about at length will remain here.

Enjoy

Michael Still: One Tree and Painter

Sun, 2015-04-12 17:28
Paul and I set off to see two trigs today. One Tree is on the ACT border and is part of the centenary trail. Painter is a suburban trig in Belconnen. Much fun was had, I hope I didn't make Paul too late for the wedding he had to go to.



 



Interactive map for this route.



Interactive map for this route.



Tags for this post: blog pictures 20150412-one_tree_painter photo canberra bushwalk trig_point

Related posts: Goodwin trig; Big Monks; Narrabundah trig and 16 geocaches; Cooleman and Arawang Trigs; A walk around Mount Stranger; Forster trig



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James Purser: So, it's been a while

Sat, 2015-04-11 22:31

Well as you can see it's been a while since I last posted here, just over a year in fact, so it's time for a bit of a clean up.

As you can see I've started redesigning things, updated the theme so that it's a bit more mobile friendly (as in will be viewable on mobile), added in the feeds from Angry Beanie and I'll be doing more work around including information about the projects I'm working on such as Govchecker and Zooborns for Android

I'm also going to try and do more writing here. I think I've fallen into the trap of not writing because I use twitter or facebook instead. Blogging though helps me to focus my thoughts a bit more so we'll see how that goes.

Anyway, this blog as ever is a work in progress, so we'll see what comes.

Oh and one more thing, you'll see that I've replaced the drupal comments system with disqus instead. This way we can hopefully avoid the comment spam problem I was getting before.

Blog Catagories: Developmentangry beanie

Ben Martin: Tiny Tim improves and gets Smaller

Fri, 2015-04-10 23:11
I finally switched Tiny Tim over to a lipo battery. Almost everything worked when I tested the new battery, the only thing that failed in a major way were the two 2812 LEDs which, either didn't come on or came on for a very quick moment and went dark. So Tim is now smaller again without the "huge" AA battery pack at it's tail.





The 2812 story was interesting. It wasn't going to be happy jumping to the 7.6v of the 2S lipo. So I tried various voltage divider setups which didn't work either. I ended up using a common 5v regulator and the lights work fine again. I think I was maybe using too high resistor values in the divider and the 2812s didn't like it. At any rate, they apparently want a good regulated power source, and I wasn't giving it one before I switched over to using the regulator.



On the whole, going from 5-6v of the AA pack to 7.6v has made it a snappier mover. I tried it initially with the battery on the bench and found it would lift the back off the desk under hard break.



Next up is probably attaching a claw or drop mechanism and ultrasound sensor and then take on the Sparkfun autonomous ping-pong ball into cup challenge. I'll probably control it via wireless from a second on board micro-controller. The drop, ultrasound, and autonomous navigation micro (and additional battery) can all be put into a single "module" that I can then bolt to Tim. All the navigation micro needs to do is control the differential drive like a remote control would. This way, the existing micro etc on Tim doesn't change at all in order for the challenge to be accepted.





Clinton Roy: clintonroy

Fri, 2015-04-10 19:28

Writing your first conference proposal can be difficult, so we’re running a working bee at UQ on Saturday 11th (in conjunction with Humbug). If you’ve never written a conference proposal before, or you’d like yours given the once over, please come along, register over at meetup.



Filed under: Uncategorized

Stewart Smith: Towards (and beyond) ONE MILLION queries per second

Fri, 2015-04-10 17:26

At Percona Live MySQL Conference 2015 next week I’ll be presenting on “Towards One MILLION queries per second” on 14th April at 4:50pm in Ballroom A.

This is the story of work I’ve been doing to get MySQL executing ONE MILLION SQL queries per second. It involves tales of MySQL, tales of the POWER8 Processor and a general amount of fun in extracting huge amounts of performance.

As I speak, I’m working on some even more impressive benchmark results! New hardware, new MySQL versions and really breaking news on MySQL scalability.

Michael Still: Thinking time

Fri, 2015-04-10 09:29
I've had a lot of things to think about this week, so I've gone on a few walks. I found some geocaches along the way, but even better I think my head is a bit more sorted out now.



Interactive map for this route.



Interactive map for this route.



Interactive map for this route.



Tags for this post: blog canberra bushwalk

Related posts: Goodwin trig; Big Monks; Geocaching; Confessions of a middle aged orienteering marker; A quick walk through Curtin; Narrabundah trig and 16 geocaches



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Brendan Scott: brendanscott

Wed, 2015-04-08 16:30

The WSJ has an interesting article about an investor who is funding claims to invalidate patents. The logic is that he shorts the stock. When the patent is invalidated, the stock plummets. He sells the stock – profit.  Hat tip: Andrew Wilson



Rusty Russell: Lightning Networks Part IV: Summary

Wed, 2015-04-08 14:28

This is the fourth part of my series of posts explaining the bitcoin Lightning Networks 0.5 draft paper.  See Part I, Part II and Part III.

The key revelation of the paper is that we can have a network of arbitrarily complicated transactions, such that they aren’t on the blockchain (and thus are fast, cheap and extremely scalable), but at every point are ready to be dropped onto the blockchain for resolution if there’s a problem.  This is genuinely revolutionary.

It also vindicates Satoshi’s insistence on the generality of the Bitcoin scripting system.  And though it’s long been suggested that bitcoin would become a clearing system on which genuine microtransactions would be layered, it was unclear that we were so close to having such a system in bitcoin already.

Note that the scheme requires some solution to malleability to allow chains of transactions to be built (this is a common theme, so likely to be mitigated in a future soft fork), but Gregory Maxwell points out that it also wants selective malleability, so transactions can be replaced without invalidating the HTLCs which are spending their outputs.  Thus it proposes new signature flags, which will require active debate, analysis and another soft fork.

There is much more to discover in the paper itself: recommendations for lightning network routing, the node charging model, a risk summary, the specifics of the softfork changes, and more.

I’ll leave you with a brief list of requirements to make Lightning Networks a reality:

  1. A soft-fork is required, to protect against malleability and to allow new signature modes.
  2. A new peer-to-peer protocol needs to be designed for the lightning network, including routing.
  3. Blame and rating systems are needed for lightning network nodes.  You don’t have to trust them, but it sucks if they go down as your money is probably stuck until the timeout.
  4. More refinements (eg. relative OP_CHECKLOCKTIMEVERIFY) to simplify and tighten timeout times.
  5. Wallets need to learn to use this, with UI handling of things like timeouts and fallbacks to the bitcoin network (sorry, your transaction failed, you’ll get your money back in N days).
  6. You need to be online every 40 days to check that an old HTLC hasn’t leaked, which will require some alternate solution for occasional users (shut down channel, have some third party, etc).
  7. A server implementation needs to be written.

That’s a lot of work!  But it’s all simply engineering from here, just as bitcoin was once the paper was released.  I look forward to seeing it happen (and I’m confident it will).

Simon Lyall: Reading the Lord of the Rings aloud

Wed, 2015-04-08 11:28

The reading project that I am working on is a re-read of the Lord of the Rings. I’ve read the book/trilogy around a dozen times over the years but the two main differences this time are that I am reading it aloud and that I am consulting a couple of commentaries as I go. The references works I am using are The Lord of the Rings: A Reader’s Companion and the The Lord of the Rings Reread series by Kate Nepveu. The Companion is a fairly large book (860 pages) that follows the text page by page and gives explanations for words, characters and the history/development of the text. These can range from a simple definition to a couple of pages on a specific topic or character. The reread has a quick synopsis at the start of the article for each chapter and then some commentary by Kate followed by some comments from her readers (which I usually only quickly skim).

I started my read-aloud on February 15th 2015 and I am now ( April 7th ) just past the half-way point ( I completed The Fellowship of the Ring on March 27th) . My process is to read the text for 30-60 minutes ( I’m reading the three-book 1979 3rd edition paperback edition, which amusingly has various errors that the Reader’s Companion points out as I go) which gets me though 5-10 pages. I read aloud everything on the page including chapter titles, songs, non-English words and footnotes. A few times I have checked the correct pronunciation of words ( Eomer is one ) but otherwise I try not to get distracted. Once I finish for the session I open the Reader’s Companion and check the entries for the pages I have just read and at the end of each chapter ( chapters are usually around 20-30 pages) I have a look at Kate’s blog entry. I try an read most days and sometimes do extras on weekends.

One thing I really need to say is that I really am enjoying the whole thing. I love the book (like I said I’ve read it over a dozen times) and reading it aloud makes the experience even better. The main difference is that I do not skip over words/sentences/paragraphs which tends to happen when I read normally. So I don’t miss phrases like the description of Lake Hithoel:

The sun, already long fallen from the noon, was shining in a windy sky. The pent waters spread out into a long oval lake, pale Nen Hithoel, fenced by steep grey hills whose sides were clad with trees. At the far southern end rose three peaks. The midmost stood somewhat forward from the others and sundered from them, an island in the waters, about which the flowing River flung pale shimmering arms. Distant but deep there came up on the wind a roaring sound like the roll of thunder heard far away.



Nor do I skip the other little details that are easy to miss, like Grishnakh and his Mordor Orcs leaving the rest of the group for a couple of days on the plains of Rohan or the description of country leading up to the west gate of Moria. Although I do wish I’d seen the link to the map of Helm’s Deep halfway down this page before I’d read the chapter as it would have made things clearer. The Companion is also good at pointing out how things fit in the chronology, so when somebody gazes at the horizon and sees a cloud of smoke it will say what event elsewhere in the book (or other writing) that is from. You also get a great feel for Tolkien’s language and words and his vivid descriptions of scenes and landscape (often up to a page long) such the example above. Although I do find he uses “suddenly” an awful lot when he has new events/people break into the narrative.

The readers companion is a great resource, written by two serious Tolkien scholars but intended for general readers rather than academics. Kate Nepveu’s articles are also very useful in giving a more opinionated and subjective commentary. I would definitely recommend the experience to others who are fans of the Lord of the Rings. I’m not sure how well it would work with other books but certainly it enhances a work I already know well and love.

At the current rate I am expecting to finish some time in June or July. The next project I’m planning is Shakespeare’s plays. I am planning on reading each one (multiple times including possibly at least once aloud) and watching the BBC Television Shakespeare and other adaptations and commentaries. My plan is that I’ll cover the majority of them  but I’ll see how I go, However I’d like to at least get though the major ones.

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Rusty Russell: Lightning Networks Part III: Channeling Contracts

Mon, 2015-04-06 21:28

This is the third part of my series of posts explaining the bitcoin Lightning Networks 0.5 draft paper.

In Part I I described how a Poon-Dryja channel uses a single in-blockchain transaction to create off-blockchain transactions which can be safely updated by either party (as long as both agree), with fallback to publishing the latest versions to the blockchain if something goes wrong.

In Part II I described how Hashed Timelocked Contracts allow you to safely make one payment conditional upon another, so payments can be routed across untrusted parties using a series of transactions with decrementing timeout values.

Now we’ll join the two together: encapsulate Hashed Timelocked Contracts inside a channel, so they don’t have to be placed in the blockchain (unless something goes wrong).

Revision: Why Poon-Dryja Channels Work

Here’s half of a channel setup between me and you where I’m paying you 1c: (there’s always a mirror setup between you and me, so it’s symmetrical)

Half a channel: we will invalidate transaction 1 (in favour of a new transaction 2) to send funds.

The system works because after we agree on a new transaction (eg. to pay you another 1c), you revoke this by handing me your private keys to unlock that 1c output.  Now if you ever released Transaction 1, I can spend both the outputs.  If we want to add a new output to Transaction 1, we need to be able to make it similarly stealable.

Adding a 1c HTLC Output To Transaction 1 In The Channel

I’m going to send you 1c now via a HTLC (which means you’ll only get it if the riddle is answered; if it times out, I get the 1c back).  So we replace transaction 1 with transaction 2, which has three outputs: $9.98 to me, 1c to you, and 1c to the HTLC: (once we agree on the new transactions, we invalidate transaction 1 as detailed in Part I)

Our Channel With an Output for an HTLC

Note that you supply another separate signature (sig3) for this output, so you can reveal that private key later without giving away any other output.

We modify our previous HTLC design so you revealing the sig3 would allow me to steal this output. We do this the same way we did for that 1c going to you: send the output via a timelocked mutually signed transaction.  But there are two transaction paths in an HTLC: the got-the-riddle path and the timeout path, so we need to insert those timelocked mutually signed transactions in both of them.  First let’s append a 1 day delay to the timeout path:

Timeout path of HTLC, with locktime so it can be stolen once you give me your sig3.

Similarly, we need to append a timelocked transaction on the “got the riddle solution” path, which now needs my signature as well (otherwise you could create a replacement transaction and bypass the timelocked transaction):

Full HTLC: If you reveal Transaction 2 after we agree it’s been revoked, and I have your sig3 private key, I can spend that output before you can, down either the settlement or timeout paths.

Remember The Other Side?

Poon-Dryja channels are symmetrical, so the full version has a matching HTLC on the other side (except with my temporary keys, so you can catch me out if I use a revoked transaction).  Here’s the full diagram, just to be complete:

A complete lightning network channel with an HTLC, containing a glorious 13 transactions.

Closing The HTLC

When an HTLC is completed, we just update transaction 2, and don’t include the HTLC output.  The funds either get added to your output (R value revealed before timeout) or my output (timeout).

Note that we can have an arbitrary number of independent HTLCs in progress at once, and open and/or close as many in each transaction update as both parties agree to.

Keys, Keys Everywhere!

Each output for a revocable transaction needs to use a separate address, so we can hand the private key to the other party.  We use two disposable keys for each HTLC[1], and every new HTLC will change one of the other outputs (either mine, if I’m paying you, or yours if you’re paying me), so that needs a new key too.  That’s 3 keys, doubled for the symmetry, to give 6 keys per HTLC.

Adam Back pointed out that we can actually implement this scheme without the private key handover, and instead sign a transaction for the other side which gives them the money immediately.  This would permit more key reuse, but means we’d have to store these transactions somewhere on the off chance we needed them.

Storing just the keys is smaller, but more importantly, Section 6.2 of the paper describes using BIP 32 key hierarchies so the disposable keys are derived: after a while, you only need to store one key for all the keys the other side has given you.  This is vastly more efficient than storing a transaction for every HTLC, and indicates the scale (thousands of HTLCs per second) that the authors are thinking.

Next: Conclusion

My next post will be a TL;DR summary, and some more references to the implementation details and possibilities provided by the paper.

 

[1] The new sighash types are fairly loose, and thus allow you to attach a transaction to a different parent if it uses the same output addresses.  I think we could re-use the same keys in both paths if we ensure that the order of keys required is reversed for one, but we’d still need 4 keys, so it seems a bit too tricky.

Sridhar Dhanapalan: Twitter posts: 2015-03-30 to 2015-04-05

Mon, 2015-04-06 00:26

Michael Still: Bendora Arboretum and Bulls Head trig

Sun, 2015-04-05 09:28
Prompted largely by a not very detailed entry in a book, a bunch of friends and I went to explore Bendora Arboretum. The arboretum was planted in the 1940's as scientific experiments exploring what soft woods would grow well in our climate -- this was prompted by the large amount of wood Australia was importing at the time. There were 34 Arboreta originally, but only this one remains. The last three other than this one were destroyed in the 2003 bush fires.



This walk appears in Best Bush, Town and Village Walks in and around the ACT by Marion Stuart, which was the inspiration for this outing. The only thing to note with her description is that the walk is a fair bit longer than she describes -- its 2km from the locked gate to the hut, which means a 4km return walk before you explore the arboretum at all. The arboretum has received some attention from the ACT government recently, with new signage and a fresh gravel pass. Also please note this area might only be accessible by four wheel drive in winter, which is not mentioned in the book.



We also did a side trip to Bulls Head trig, which was interesting as its not the traditional shape.



                                       



See more thumbnails



Interactive map for this route.



Interactive map for this route.



Tags for this post: blog pictures 20150404-bendora_bulls_head photo canberra bushwalk trig_point

Related posts: Goodwin trig; Big Monks; Narrabundah trig and 16 geocaches; Cooleman and Arawang Trigs; One Tree and Painter; A walk around Mount Stranger



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