Bitcoin Forum

Economy => Service Discussion => Topic started by: Amitabh S on June 13, 2015, 11:40:01 AM



Title: What does "taint analyis" on blockchain.info really mean?
Post by: Amitabh S on June 13, 2015, 11:40:01 AM
I have always wondered what they meant by that. Clicking on it gives some bunch of addresses and a "taint percentage". Is there any proper document explaining these terms?

http://i58.tinypic.com/2n821s0.gif

I guess its been asked before. So please point me to the link.


Title: Re: What does "taint analyis" on blockchain.info really mean?
Post by: Amitabh S on June 13, 2015, 12:26:35 PM
https://blockchain.info/taint/1JArS6jzE3AJ9sZ3aFij1BmTcpFGgN86hA

HTH


Thats not exceptionally clear. How is the percent calculated? Is it the number of times, or the amount of coins?


Title: Re: What does "taint analyis" on blockchain.info really mean?
Post by: dogie on June 13, 2015, 12:30:26 PM
Here is the full quote:

Quote
The taint is the percentage of funds received by an address that can be traced back to another address. An example of a taint analysis is: https://blockchain.info/taint/1dice6GV5Rz2iaifPvX7RMjfhaNPC8SXH

Tldr its the proportional origin of the coins (expressed in %). So if A sent to a fresh address B, the taint analysis for B would be 100% A. If C then sent the same amount to B, the taint analysis for B would then show 50% A and 50% C. [Unless I have also misunderstood it? Does it go back multiple levels?]


Title: Re: What does "taint analyis" on blockchain.info really mean?
Post by: madonnino on June 13, 2015, 12:34:54 PM
with this function you can see what is the address that exchanged bitcoin with your wallet , it also serves to test if mixer works well


Title: Re: What does "taint analyis" on blockchain.info really mean?
Post by: laurentmt on June 13, 2015, 03:39:50 PM
Dogie is correct about the interpretation and unless things have changed, the metric goes back to multiple levels.

Quote
Unfortunately they don't seem to explain it very clearly themselves but my guess is that what really matters is the % of BTC in terms of UTXOs that can be clearly traced between the two parties (also it is not clear if that includes "levels" of indirection).

So if Alice was sending to Bob a total of 1 BTC but used a mixer to do this assuming that the mixer did its job correctly the % of Alice's coins that can be directly traced to Bob should be no bigger than of basically any other involved party (say 1%).

Taint is a broken concept for cryptocurrencies like bitcoin (and let's forget monero, zerocash, ...).
Computation of taint requires that you can determine with certainty the link between inputs & outputs of a transaction. Systems like mixers or coinjoin break this link. The best you can get is a probabilistic metric.




Title: Re: What does "taint analyis" on blockchain.info really mean?
Post by: gmaxwell on June 14, 2015, 01:13:25 AM
The computation on BC.i is darn near a random number generator. The main thing it accomplishes is making people think they're more (or, infrequently, less) private than they are.


Title: Re: What does "taint analyis" on blockchain.info really mean?
Post by: OROBTC on June 14, 2015, 04:13:32 PM
...

I hear and respect what gmaxwell says, but perhaps the best use of a current (existing) & decent mixing service is that it provides some privacy.  I am not worried about hiding my BTC trail from .gov (perhaps they can track BTC very easily or even own / can hack the mixers).  But, the mixers make it easier to hide the trail from casual or even Junior Varsity Snoops (mafias maybe too).

*   *   *

Is there anyone else who does "taint analysis"?  It would be interesting, to say the least, to see if both analyses would arrive at a similar percentage of taint between BTC addresses.