# HG changeset patch # User Christian Urban # Date 1481818265 0 # Node ID 66d2bc189b88d3e61e395f28e7f4b7ad60dfe1e7 # Parent 645d0c1aefb1a677cf07f61760c661c0eb6317d2# Parent 0d40d1f973e02bf5e745ae8c3f4bc13cb92e310a merged diff -r 645d0c1aefb1 -r 66d2bc189b88 handouts/ho07.tex --- a/handouts/ho07.tex Thu Dec 15 16:09:57 2016 +0000 +++ b/handouts/ho07.tex Thu Dec 15 16:11:05 2016 +0000 @@ -86,6 +86,28 @@ %data regarding your general usage of your computer, including which %programs you run and for how long. +% Businesses are already using customised pricing online based on +% information they can glean about you. It is hard to know how +% widespread the practice is; companies keep their pricing strategies +% closely guarded and are wary of the bad PR price discrimination +% could pose. However, it is clear that a number of large retailers +% are experimenting with it. Staples, for example, has offered +% discounted prices based on whether rival stores are within 20 miles +% of its customers’ location. Office Depot has admitted to using its +% customers’ browsing history and location to vary its range of offers +% and products. A 2014 study from Northeastern University found +% evidence of “steering” or differential pricing at four out of 10 +% general merchandise websites and five out of five travel +% websites. (Steering is when a company doesn’t give you a customised +% price, but points you towards more expensive options if it thinks +% you will pay more.) The online travel company Orbitz raised +% headlines in 2012 when it emerged that the firm was pointing Mac +% users towards higher-priced hotel rooms than PC users. + + +%%% government will overwrite your wishes if it is annoymous +%% https://www.lightbluetouchpaper.org/2016/12/05/government-u-turn-on-health-privacy/ + \section*{Handout 6 (Privacy)} The first motor car was invented around 1886. For ten years, diff -r 645d0c1aefb1 -r 66d2bc189b88 handouts/ho08.pdf Binary file handouts/ho08.pdf has changed diff -r 645d0c1aefb1 -r 66d2bc189b88 handouts/ho08.tex --- a/handouts/ho08.tex Thu Dec 15 16:09:57 2016 +0000 +++ b/handouts/ho08.tex Thu Dec 15 16:11:05 2016 +0000 @@ -839,6 +839,61 @@ simply cool. But still the entire Bitcoin ecosystem is in my humble opinion rather fragile. + +\subsubsection*{Isn't there anything good with Bitcoins?} + +As you can see, so far my argument was that yes the Bitcoin system is +based on a lot of very cool technical ideas, but otherwise it is a big +scam. You might wonder if there is not something good (in terms of +valuable for civilisation) in the bitcoin system? I think there is +actually: diamonds are quite valuable and because of this can be +used as a form of `money'---just remember the song with the line +`diamonds are forever'. + +The problem with diamonds is that in some places where they are found, +they also fund some stupid wars. You like to set up a usable system +whereby you can check whether a diamond comes from a reputable source +(not funding any wars) or from a dodgy source. For this you have to +know that `clearing houses' for diamonds can engrave with lasers +unique numbers inside the diamonds. These engravings are invisible to +the naked eye and as far as I remember these numbers cannot be removed, +except by destroying the diamond. Even if it can be removes, diamonds +without the number cannot (hopefully) be sold. + +How do bitcoins come into the picture? The idea is called +\emph{coloured coins}, where you attach some additional information to +some `coins'. In the diamond example the bitcoin transactions are +supposed to act as a certificate where diamonds are from (reputable +sources or not). For this you have to know that you can attach a very +short custom-made message with each bitcoin transaction. So you would +record the diamond number inside the message. + +Now, you would set the system up so that a trusted entity (which +exists in the diamond world) buys with their public key bitcoins (or +smaller amounts). These trusted entities are essentially the places +that also cut the raw diamonds. The idea is whenever you buy a +diamond, you like to have also the corresponding bitcoin +transaction. If you want to sell the diamond, you make a transaction +to the new owner. The new owner will ask for this message, because +otherwise he/she cannot sell it later on. + +The advantage is that for each diamond you can trace back that the +transaction must have originated from the trusted entity. If yes, your +diamond will be sellable. If you do not have the message, the diamond +comes from a dodgy source and will (hopefully) not be sellable later +on. In this way you skew the incentives such that only legitimate +diamond are of value. The bitcoin system just helps with being able to +check whether the message originates from the trusted entity or +not....you do not have to consult anybody else and pay money for this +consultation. Or in any way reveal your identity by such a consultation +(the police might just keep a particularly close an eye on who contacts +such a clearing house). + +Since we hopefully all agree that funding stupid wars is bad, any +system that can starve funds for such wars must be good. Piggy-bagging +on the trust established by the bitcoin system on the public block chain +makes such a system realisable. + \subsubsection*{Further Reading} Finally, finally, the article diff -r 645d0c1aefb1 -r 66d2bc189b88 slides/slides08.pdf Binary file slides/slides08.pdf has changed