Stealth address with SX (anonymous payments)

[e4xit]

pity people don't have software to do common tasks and need to resort to installing dodgy malware. anyway that will change with time.

btw first stealth tx: https://blockchain.info/tx/63e75e43de21b73d7eb0220ce44dcfa5fc7717a8decebb254b31ef13047fa518

testing code for those interested: https://github.com/genjix/stealth

(implementation detail: it's currently using number_bits=0 so not using the prefix optimisation. this is only for my testing purposes.)

Now that's cool!..

Also:

Code:

OP_RETURN 06deadbeef0276044981dc13bdc5e118b63c8715f0d1b00e6c0814d778668fa6b594b2a0ffbd

deadbeef?

[genjix]

thanks for appreciation of my work, it's a nice donation. as an opensource coder, I love it when people to steal my work.

e4xit- yeah the deadbeef is a 4 byte nonce. see:
https://wiki.unsystem.net/index.php/DarkWallet/Stealth

it's a (currently) unused scalability feature that will be enabled later once the number of stealth txs goes up.
people will be able to reissue stealth keys and narrow the space of possible candidate txs from the blockchain to reduce the processing and traffic they need. in the beginning we might not even split the space so everyone's transactions can protect each other.
normally you should brute-force different values until you find a hash where the first N bits matches what's specified by the stealth address. Since I'm using N=0, it doesn't matter what I put there - I'm using this for developing the server side stealth features in obelisk.

it's a very smart feature from peter todd. bloom filters is not scalable, efficient nor really that private.

[drrussellshane]

I tried to install this on Ubuntu using:

Code:

$ wget http://sx.dyne.org/install-sx.sh
$ sudo bash ./install-sx.sh

and it said that I needed some things, so I told it to get and install the packages, and all was going well until it told me how much space was required and asked if I'd like to continue.... when I pressed "Y", it merely returned "Abort."

I tried to use sx after the (failed) installation, but it told me that sx was not installed, and suggested that I install something (which I am quite certain is not the sx/libbitcoin stuff).

Thus, I cannot use sx.

Any ideas?

[ColonelCrypto]

btw first stealth tx: https://blockchain.info/tx/63e75e43de21b73d7eb0220ce44dcfa5fc7717a8decebb254b31ef13047fa518

http://sinsip.com/Jl.jpg

[BTC5OOO]

pity people don't have software to do common tasks and need to resort to installing dodgy malware. anyway that will change with time.

btw first stealth tx: https://blockchain.info/tx/63e75e43de21b73d7eb0220ce44dcfa5fc7717a8decebb254b31ef13047fa518

testing code for those interested: https://github.com/genjix/stealth

(implementation detail: it's currently using number_bits=0 so not using the prefix optimisation. this is only for my testing purposes.)

Unable to decode input address

/\off the chain!!!! =) *many thanks & keep up the good work!

[genjix]

thx for flattery. I also take donations: 1Fufjpf9RM2aQsGedhSpbSCGRHrmLMJ7yY

Stealth blockchain stuff is now part of libbitcoin, obelisk .etc

More info: https://wiki.unsystem.net/index.php/DarkWallet/Stealth#Toys

You can lookup the transactions in the blockchain, do the comparisons and find candidate results.

Documentation about everything is on the wiki for developers.

Code:

$ sx fetch-stealth
Usage: fetch-stealth NUMBER_BITS BITFIELD [FROM_HEIGHT]
$ sx fetch-stealth 2 deadbeef
DEBUG: ephemkey: 024398667c6a11652ae80fe6370e140cc67d4f82fb8310122cdaddae1524dad9e0 address: 1Nw1EKu8Y6mPGhMGyrKPS9TZWDyTPLvi8a tx_hash: 6a6246ccc7cb9427efee85dd3c7b80164f8a61213a7ce357b8cfd3816f59aab9
DEBUG: ephemkey: 02828c82feeae6ea5526e1b17adf3a7e9a1ee53680fc0ba651a3e7c1a99529ef24 address: 1QJSNUqt8HRygcNvbyYHQw5NizMCBkixsb tx_hash: 75885e50418cee0e527316df1f740ef6bc6b60a4b325c6d8d20e00a053cd27f9
DEBUG: ephemkey: 03a3e941099eda82cee7727e238e34283611e71debe063ed5029b51336060de080 address: 1KnByqTSjWbh5gb2K74Nkdf6oU5VMtfJqf tx_hash: 6deba5f43c85d881fa88fd40f53ab2c825682d4829db0154982ddf9f60a9a0c7
DEBUG: ephemkey: 024b4d9a7564644deb94743872e6823f87c1ce8cca7c2ba84cd926dea5498a0a53 address: 14DcERFvDPYTr1PHqphqvQuawvAoFTsKgH tx_hash: ba058ad8330e56b5cb18c08d98c465a91d7ce4d1bc5ac10f1384a0619a3559f4

[tvbcof]

This is pretty Cool!  Exchanging private keys is, I think, a pretty powerful way to increase privacy and throw a monkey-wrench into the methods of user tracking.  I suspect that it is a big factor in why the hammer came down on Casascius.

The natural 'solution' to the 'problem' here would be to simply blacklist transactions signed by an un-mapped private key.  To 'get there' we need a working taint authority.  The 'Bitcoin Source Code Co-Author' (Alex Waters) is hard at work on the problem.   Also we need a reasonably healthy exchange economy with operators who can be realistically forced to honor the taint authorities' output (Overstock, TigerDirect, etc.)  Then just a little time to roll things in in a manner which won't cause excessive resistance ['terrorist' -> 'criminals(bad)' - > 'criminal(fraud)' -> 'tax cheats' -> 'unknown users'].

Will this work?  Time will tell I guess.  Economic principles are distinctly on the side of tainting being highly effective if it can be successfully bootstrapped.  My read on things.

[genjix]

good analysis. not many people are reading between the lines or thinking that far ahead. history teaches us much.

[ShadowOfHarbringer]

good analysis. not many people are reading between the lines or thinking that far ahead. history teaches us much.

So i guess we need this (and CoinSwap/CoinJoin/CoinControl) in reference client ASAP ? Would it be difficult to do ?

[tvbcof]

Hey Genjix,

This thread got me interested enough in your work to try to include some of it in my personal little build system thingy.  Obviously this is sensitive stuff and I'm security conscious and careful about how and what I put on my systems.  I found just identifying your work (and associated work of others) on the global internet to be difficult and confusing.

 - We've got 'en.bitcoin.it/wiki' stuff pointing to dyne.org stuff.

 - We've got dyne.org stuff pointing to github/gengix stuff (which 404's, but as recently as a few days ago you quoted it seems.)

 - We've got github/spesmilo stuff.

 - We've got 'unsystem.net' stuff.

 - We've got a variety of install scripts which run as root and download various dependencies, up-to-date tools, etc.

If you would feel inclined to give bit of a run-down of the history and locations of your work and related work that would be great.  Likewise, trying to chase down loose documentation and delete or update it would also be helpful.

Your work is 'disruptive inside of disruptive', and in my opinion it is especially important to be precise and rigorous insofar as distribution is concerned.  My opinion.

[genjix]

Thanks, we're trying to be organised but it's tricky sometimes.

Basically the main production repos are:

https://github.com/darkwallet
https://github.com/spesmilo/

My personal repo contains mostly experimental/testing stuff which later enters into the above repos as it matures (stufflike Obelisk, stealth, databases, .etc). My toys:

https://github.com/genjix/

The wiki contains a lot of our internal documentation for our projects:

https://wiki.unsystem.net/

Also our IRC channel is important- Freenode #darkwallet (would be cool to see you on there and coordinate). We are offering free bouncers BTW if anyone wants one: https://wiki.unsystem.net/index.php/DarkWallet/Bouncer

The unSYSTEM website should be our landing page, and we plan to syndicate a lot more stuff there but it needs work on both content and tech side (https isn't working):

http://unsystem.net/

d3 (admin for our projects) has setup https://libbitcoin.org/ now and I plan to move the website there, but we need to get the builds working, easy for me to push updates .etc

We also have mailing lists:

https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/unsystem
https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/libbitcoin
https://lists.unsystem.net/cgi-bin/mailman/listinfo/darkwallet

We definitely need to organise all these resources better. Would be cool to talk on IRC so we can plan if you have some ideas, and we can coordinate with the admin / other people.

[BTC5OOO]

https://libbitcoin.org/

some genius spelled " revoltionary " wrong or is dat on purpose? lol =)

[ADgordo]

Forgive my ignorance but why was their an undecodable output on that stealth transaction?

[justusranvier]

The natural 'solution' to the 'problem' here would be to simply blacklist transactions signed by an un-mapped private key.  To 'get there' we need a working taint authority.  The 'Bitcoin Source Code Co-Author' (Alex Waters) is hard at work on the problem.

So is Mike Hearn.

[justusranvier]

If a sender exchanges one secret with the recipient, it's currently my understanding that every payment that sender creates would have the exact same output script.

It would be a useful property if individuals could exchange a secret once, and generate a deterministic series of output scripts from that point on.

[tvbcof]

The natural 'solution' to the 'problem' here would be to simply blacklist transactions signed by an un-mapped private key.  To 'get there' we need a working taint authority.  The 'Bitcoin Source Code Co-Author' (Alex Waters) is hard at work on the problem.

So is Mike Hearn.

I have to admit that my first thought when he mentioned that he finally quit Google was whether he had hired on at CoinValidation.  I thought it would be rude to ask

I also neglected to wish him the best and hope that he feels a sense of relief that one gets from breaking free of the of the legal, moral, and ethical constraints that some people feel in working for an organization such as Google given the priorities which such organizations must adhere to.  This actually would not have been tongue-n-cheek but rather completely earnest.

That said, I do have a legitimate fear that Hearn can do even more 'damage' (as I, and I suspect you also, would define it) on the 'outside'.

[genjix]

yeah he quit google to go work for circle

http://www.coindesk.com/bitcoin-abandons-anti-establishment-wall-street/

these guys are not into bitcoin for freedom and the new tools it gives us to enable new forms of organisation for humans. they see it as a convenience for consumers to paper over the cracks in the current finance system and perpetuate their corporate culture.

[piotr_n]

Had he been smart, he would have chosen a right team to play for.  

[marcus_of_augustus]

yeah he quit google to go work for circle

http://www.coindesk.com/bitcoin-abandons-anti-establishment-wall-street/

these guys are not into bitcoin for freedom and the new tools it gives us to enable new forms of organisation for humans. they see it as a convenience for consumers to paper over the cracks in the current finance system and perpetuate their corpro-facist culture.

ftfy

[genjix]

oh fuck it's really happening... bitcoin is under attack

http://venturebeat.com/2014/03/26/circle-raises-17m-to-bring-bitcoin-out-of-the-shadows-for-merchants-consumers/

"Launching today in closed beta — with a fresh $17 million in its pocket —
Circle claims its first consumer product enables “faster transactions,
lower costs, greater privacy safeguards and increased protection against
fraud and identity theft.” The company plans to provide tools for both
consumers and businesses, with the overall goal of reducing “the friction
and risk that is currently associated with Bitcoin.”"

> faster transactions, lower costs, greater privacy safeguards and
increased protection against fraud and identity theft.
> increased protection against fraud.
> protection against fraud

> provide tools for both consumers and businesses, with the overall goal
of reducing “the friction and risk that is currently associated with
Bitcoin.”
> reducing the friction and risk
> reducing the risk

funny enough mike hearn quit google to work for circle.

http://www.coindesk.com/bitcoin-abandons-anti-establishment-wall-street/

Allaire is blunt about the transition bitcoin is going through, saying
it’s “absolutely” moving away from its libertarian roots.

lovely. they are going to rescue bitcoin from us.

reducing the risk is newspeak for censorship
protection against fraud is codeword for surveillance.