jm + currency   7

Bank of the Underworld - The Atlantic
Prosecutors analyzed approximately 500 of Liberty Reserve’s biggest accounts, which constituted 44 percent of its business. The government contends that 32 of these accounts were connected to the sale of stolen credit cards and 117 were used by Ponzi-scheme operators. All of this activity flourished, prosecutors said, because Liberty Reserve made no real effort to monitor its users for criminal behavior. What’s more, records showed that one of the company’s top tech experts, Mark Marmilev, who was also arrested, appeared to have promoted Liberty Reserve in chat rooms devoted to Ponzi schemes.

(via Nelson)
scams  fraud  crime  currency  the-atlantic  liberty-reserve  ponzi-schemes  costa-rica  arthur-budovsky  banking  anonymity  cryptocurrency  money-laundering  carding 
april 2015 by jm
The missing MtGox bitcoins
Most or all of the missing bitcoins were stolen straight out of the MtGox hot wallet over time, beginning in late 2011. As a result, MtGox operated at fractional reserve for years (knowingly or not), and was practically depleted of bitcoins by 2013. A significant number of stolen bitcoins were deposited onto various exchanges, including MtGox itself, and probably sold for cash (which at the bitcoin prices of the day would have been substantially less than the hundreds of millions of dollars they were worth at the time of MtGox's collapse).

MtGox' bitcoins continuously went missing over time, but at a decreasing pace. Again by the middle of 2013, the curve goes more or less flat, matching the hypothesis that by that time there may not have been any more bitcoins left to lose. The rate of loss otherwise seems unusually smooth and at the same time not strictly relative to any readily available factors such as remaining BTC holdings, transaction volumes or the BTC price. Worth pointing out is that, thanks to having matched up most of the deposit/withdrawal log earlier, we can at this point at least rule out the possibility of any large-scale fake deposits — the bitcoins going into MtGox were real, meaning the discrepancy was likely rather caused by bitcoins leaving MtGox without going through valid withdrawals.
mtgox  bitcoin  security  fail  currency  theft  crime  btc 
april 2015 by jm
Inside a Chinese Bitcoin Mine
The mining operation resides on an old, repurposed factory floor, and contains 2500 machines hashing away at 230 Gh/s, each. (That’s 230 billion calculations per second, per unit). [...] The operators told me that the power bill of this specific operation is in excess of ¥400,000 per month [..] about $60,000 USD.
currency  china  economics  bitcoin  power  environment  green  mining  datacenters 
august 2014 by jm
Digging for cryptocurrency: The newbie’s guide to mining altcoins
Mining Arscoins, dogecoins and litecoins -- CPU/GPU mining apps and how to run 'em
currency  bitcoin  altcoins  dogecoin  crypto  mining  ars-technica 
march 2014 by jm
java - Why not use Double or Float to represent currency?
A good canonical URL for this piece of coding guidance.
For example, suppose you have $1.03 and you spend 42c. How much money do you have left?

System.out.println(1.03 - .42); => prints out 0.6100000000000001.
coding  tips  floating-point  float  java  money  currency  bugs 
february 2014 by jm
Software Detection of Currency
Steven J. Murdoch presents some interesting results indicating that the EURion constellation may have been obsoleted:
Recent printers, scanners and image manipulation software identify images of currency, will not process the image and display an error message linking to The detection algorithm is not disclosed, however it is possible to test sample images as to whether they are identified as currency. This webpage shows an initial analysis of the algorithm's properties, based on results from the automated generation and testing of images. [...]

Initially it was thought that the "Eurion constellation" was used to identify banknotes in the newly deployed software based system, since this has been confirmed to be the technique used by colour photocopiers, and was both necessary and sufficient to prevent an item being duplicated using the photocopier tested. However further investigation showed that the detection performed by software is different from the system used in colour photocopiers, and the Eurion constellation is neither necessary nor sufficent, and in fact it probably is not even a factor.
eurion  algorithms  photoshop  security  currency  money  euro  copying  obscurity  reversing 
november 2013 by jm

Copy this bookmark: