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Welcome to my blog, which was once a mailing list of the same name and is still generated by mail. Please reply via the "comment" links.

Always interested in offers/projects/new ideas. Eclectic experience in fields like: numerical computing; Python web; Java enterprise; functional languages; GPGPU; SQL databases; etc. Based in Santiago, Chile; telecommute worldwide. CV; email.

Personal Projects

Lepl parser for Python.

Colorless Green.

Photography around Santiago.

SVG experiment.

Professional Portfolio

Calibration of seismometers.

Data access via web services.

Cache rewrite.

Extending OpenSSH.

Last 100 entries

Real-life Financial Co Without ACID Database...; Flexible Muscle-Based Locomotion for Bipedal Creatures; SQL Performance Explained; The Little Manual of API Design; Multiple Word Sizes; CRC - Next Steps; FizzBuzz; Update on CRCs; Decent Links / Discussion Community; Automated Reasoning About LLVM Optimizations and Undefined Behavior; A Painless Guide To CRC Error Detection Algorithms; Tests in Julia; Dave Eggers: what's so funny about peace, love and Starship?; Cello - High Level C Programming; autoreconf needs tar; Will Self Goes To Heathrow; Top 5 BioInformatics Papers; Vasovagal Response; Good Food in Vina; Chilean Drug Criminals Use Subsitution Cipher; Adrenaline; Stiglitz on the Impact of Technology; Why Not; How I Am 5; Lenovo X240 OpenSuse 13.1; NSA and GCHQ - Psychological Trolls; Finite Fields in Julia (Defining Your Own Number Type); Julian Assange; Starting Qemu on OpenSuse; Noisy GAs/TMs; Venezuela; Reinstalling GRUB with EFI; Instructions For Disabling KDE Indexing; Evolving Speakers; Changing Salt Size in Simple Crypt 3.0.0; Logarithmic Map (Moved); More Info; Words Found in Voynich Manuscript; An Inventory Of 3D Space-Filling Curves; Foxes Using Magnetic Fields To Hunt; 5 Rounds RC5 No Rotation; JP Morgan and Madoff; Ori - Secure, Distributed File System; Physical Unclonable Functions (PUFs); Prejudice on Reddit; Recursion OK; Optimizing Julia Code; Cash Handouts in Brazil; Couple Nice Music Videos; It Also Works!; Adaptive Plaintext; It Works!; RC5 Without Rotation (2); 8 Years...; Attack Against Encrypted Linux Disks; Pushing Back On NSA At IETF; Summary of Experimental Ethics; Very Good Talk On Security, Snowden; Locusts are Grasshoppers!; Vagrant (OpenSuse and IDEs); Interesting Take On Mandela's Context; Haskell Cabal O(n^2) / O(n) Fix; How I Am 4; Chilean Charity Supporting Women; Doing SSH right; Festival of Urban Intervention; Neat Idea - Wormholes Provide Entanglement; And a Link....; Simple Encryption for Python 2.7; OpenSuse 13.1 Is Better!; Little Gain...; More Details on Technofull Damage; Palmrest Cracked Too....; Tecnofull (Lenovo Support) Is Fucking Useless; The Neuroscientist Who Discovered He Was a Psychopath; Interpolating Polynomials; Bottlehead Crack as Pre-amp; Ooops K702!; Bottlehead Crack, AKG K701; Breaking RC5 Without Rotation; Great post thank you; Big Balls of Mud; Phabricator - Tools for working together; Amazing Julia RC5 Code Parameterized By Word Size; Chi-Square Can Be Two-Sided; Why Do Brits Accept Surveillance?; Statistics Done Wrong; Mesas Trape from Bravo; European Report on Crypto Primitives and Protocols; Interesting Omissions; Oryx And Crake (Margaret Atwood); Music and Theory; My Arduino Programs; Elliptic Curve Crypto; Re: Licensing Interpreted Code; Licensing Interpreted Code; ASUS 1015E-DS03 OpenSuse 12.3 SSD; translating lettuce feature files into stub steps files; Re: translating lettuce feature files into stub steps files; A Tale of Two Psychiatrists; The Real Reason the Poor Go Without Bank Accounts

© 2006-2013 Andrew Cooke (site) / post authors (content).

Tahoe Least Authority Filesystem / AllMyData.org

From: "andrew cooke" <andrew@...>

Date: Tue, 13 Jan 2009 01:58:38 -0300 (CLST)

This is a distributed, secure file system that uses an erasure code -
http://en.wikipedia.org/wiki/Erasure_code - and a capability access
control model - http://en.wikipedia.org/wiki/Capability-based_security

The idea is that a file is encrypted and split into fragments which are
distributed across many computers.  Only a fraction of those are needed to
reassemble the file (think RAID-5, but encrypted).

The file is identified using a URI that includes the rights (read/write)
to the data (this kind of approach always reminds me of fantasy novels
where knowing something's "true name" gives you power over it).  One
problem with that approach is that it's difficult to keep names secret -
see open issue at
http://allmydata.org/trac/tahoe/browser/docs/known_issues.txt

There's a page here that discusses possible uses for such a system -
http://allmydata.org/trac/tahoe/wiki/UseCases

The source and more info are available via via
http://allmydata.org/source/tahoe/trunk/docs/about.html and
http://allmydata.org/trac/tahoe/wiki/Doc - see papers
http://allmydata.org/~zooko/lafs.pdf and
http://allmydata.org/~warner/pycon-tahoe.html

Obviously(?) you need a gateway that provides access to the data and a
network for that gateway to work with.  If you don't want to build you own
then http://allmydata.com/ seems to be the commercial side of things - $10
a month for unlimited storage (screenshot here shows $5 -
http://www.killerstartups.com/Web-App-Tools/allmydata-com-online-storage-backup
)

Andrew

TiddlyWiki on Tahoe

From: "andrew cooke" <andrew@...>

Date: Tue, 13 Jan 2009 02:03:23 -0300 (CLST)

After all that I forgot to give the link that made me start looking at the
whole system - here's Tiddlywiki running on Tahoe.  This is a read-only
link, but you could also distribute the URI for the writable link and make
have a multi-user distributed one-page wiki :o)

http://testgrid.allmydata.org:3567/uri/URI:DIR2-RO:j74uhg25nwdpjpacl6rkat2yhm:kav7ijeft5h7r7rxdp5bgtlt3viv32yabqajkrdykozia5544jqa/wiki.html

(In practice there's no concurrent edit management in Tiddlywiki so it
would be a little frustrating at times...)

Zooko seems to be one of the main Tahoe devs (afaict that's his real name
- I started this wild-goose chase by googling for it after seeing a credit
in the Python docs!)

Andrew

OFF

From: "andrew cooke" <andrew@...>

Date: Tue, 13 Jan 2009 13:11:27 -0300 (CLST)

---------------------------- Original Message ----------------------------
From:    "Francesco Pierfederici" <fpierfed@...>
Date:    Tue, January 13, 2009 8:01 am
--------------------------------------------------------------------------

Hi Andrew,

Happy new year, first of all ;-)

Have you seen the OFF System? As far as I can tell it tries to do similar
things

http://offsystem.sourceforge.net/

Cheers,
Francesco

Re: OFF

From: "andrew cooke" <andrew@...>

Date: Tue, 13 Jan 2009 13:19:25 -0300 (CLST)

Hi,

It reminded me of something, but I don't think it was OFF (as far as I
know, I've not seen that before).  I guess there are more of these around?

There are some differences, I think - Tahoe seems to be aiming at
"reliable distributed store with capabilities" while OFF seems to be more
about deniability.  Maybe the former is more likely to make money?

Happy New Year to you too (+ Sylvia),
Andrew

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