Exact functioning: - Keyspace is reduced in a precomputation phase by calculating several thousand rendezvous points (they are hardcoded in the software but may be changed at any time). - This precomputation phase is inspired by the "Baby-Step-Giant-Step" algorithm. - The target public key is then (using ecdsa arithmetic) reduced subseqentially until hitting one of the rendezvous point. Given G is the generator point, and R=x*G the rendezvous point (which private key is known), we then may get the original privatekey by just taking PrivKey=x+iterations where iterations equals to the number of decrements were needed to hit R. Open CL Extras: - Kernel currently works with a global work size of 81920 (value can be adjusted for your graphics card). Meaning in every iteration step 81920 reductions can be made to the public key you try to crack. - Given the rendezvous point table of size 768 (may be extended anytime) we can do 81920*768 = 62914560 key comparisons per cycle. - Rendezvous-Table checks are based on just 32bit of x-coordinate to keep it fast! If a collision is found a local verification is performed on the CPU to see if its just a partial collision or a full match. This relaxes the GPU - Midpoint Feature - So even when your computer shuts down or gets restarted - the work you have already done is remembered - my HD7970 is at the moment capable of doing 150 MEGAKEYS per second - just a question of time until a rendezvous is being hit - Speedup is possible with a better Modular-Multiplication. Currently implemented as Double and Add, you could use Montgomery or FFT to get tremendous speedups Is it for beginners? No! You should be exactly know what your doing. Even though the code is straight forward, you need to know what is being done exactly and where you need to manipulate parameters if you want to change something. Documentation and Source Code? Included (as a QT Project buildable on linux and windows) Price: I am asking you 2 BTC for the whole package. It has taken me lots of time to research everything and implement it cleanly. And who knows, this tool is giving you good chances to get one of these lost 10 MILLION US$ accounts Wink Disclaimer: This project is for research purpose only, or to recover lost private keys. It may not be used for any illegal activities and I cannot be held responsible for anything you do with it.