Vanitygen

Vanitygen is a command-line vanity bitcoin address generator.

If you're tired of the random, cryptic addresses generated by regular bitcoin clients, you can use vanitygen to create a more personalized address. Add unique flair when you tell people to send bitcoins to 1stDownqyMHHqnDPRSfiZ5GXJ8Gk9dbjO. Alternatively, vanitygen can be used to generate random addresses offline.

Vanitygen accepts as input a pattern, or list of patterns to search for, and produces a list of addresses and private keys. Vanitygen's search is probabilistic, and the amount of time required to find a given pattern depends on how complex the pattern is, the speed of your computer, and whether you get lucky.

The example below illustrates a session of vanitygen. It is typical, and takes about 10 sec to finish, using a Core 2 Duo E6600 CPU on x86-64 Linux:

$ ./vanitygen 1Boat
Difficulty: 4476342
Pattern: 1Boat                                                                 
Address: 1BoatSLRHtKNngkdXEeobR76b53LETtpyT
Privkey: 5J4XJRyLVgzbXEgh8VNi4qovLzxRftzMd8a18KkdXv4EqAwX3tS

Vanitygen includes components to perform address searching on your CPU (vanitygen) and your OpenCL-compatible GPU (oclvanitygen). Both can be built from source, and both are included in the Windows binary package. Also included is oclvanityminer, the vanity address mining client. Oclvanityminer can be used to automatically claim bounties on sites such as ThePiachu's Vanity Pool.

Current version: 0.22

Windows x86+x64 binaries here. PGP signature here.

Get the source from GitHub. Includes Makefiles for Linux and Mac OS X.

Main discussion at BitCoinTalk

The latest source doesn't work properly for high-end AMD cards (7XXX and greater). Solution is to change line 459 in oclengine.c from: return quirks; to: return quirks & ~VG_OCL_AMD_BFI_INT; Windows x86+x64 binaries that solve this problem plus provide support for compressed keys here. PGP signature here. If you have any problems with the binaries, join the relevant BitCoinTalk discussion.

Expected keysearch rate

What key search rate can I expect from hardware X?

Keysearch Rates

CPU	GPU	keys/s	Comment
Core i5 750 @2.67 GHz	nVidia GTS 250	1.54 Mkey/s	110% CPU [1]
Core2 Duo 6600	nVidia GTX 285	3.5 Mkey/s	100% CPU / 90% GPU [2]
Sempron 140	AMD 5830	5.5 Mkey/s	100% CPU / 60% GPU [3]
	AMD Radeon r7 240	4 Mkey/s	[4]
Core i7	AMD 6500M	4.5 Mkey/s	98% GPU
	nVidia GeForce GTX 680M	14-16 Mkey/s	[5]
	nVidia GeForce GTX 970	38 Mkey/s	[6]
Core i7-4702MQ 2.2Ghz		1.09 Mkey/s
Core i7-4702MQ 2.2Ghz	GeForce GT750M	5.38 Mkey/s

As vanitygen performs a lot of large integer arithmetic, running it in 64-bit mode makes a huge difference in key search rate, easily a 50% improvement over 32-bit mode. If you are using a 64-bit edition of Windows, and not using a GPU, be sure to use vanitygen64.exe.

Radeon 58XX outperforms Radeon 69XX by a very comfortable margin. Oclvanitygen is sensitive to integer multiply throughput, and Radeon 58XX can multiply concurrently with other operations. At similar clocks, a hobbled Radeon 5830 will outperform a Radeon 6970.

In custom builds, CPU performance will be less than expected if the OpenSSL library is an older version (<1.0.0d) or is not built with the appropriate optimizations enabled.

Difficulty of finding a vanity

The difficult of finding a vanity address depends on its exact structure (leading letters and numbers) and how likely such an output is given the algorithms involved, which can consist of several pivots where the difficulty suddenly changes.

vanity	difficulty	Comment
1AAAAA	259,627,881
1QLbz6	259,627,881	This vanity is alphabetically before a major pivot, the RIPEMD160 hash value of 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF (address: 1QLbz7JHiBTspS962RLKV8GndWFwi5j6Qr)
1QLbz7JHiBTspS962RLKV8GndWE	2.9597E+45
1QLbz7	837,596,142	This vanity is partially after a pivot and difficulty increases
1QLbz7JHiBTspS962RLKV8GndWG	1.6489E+47	After a major pivot and 59 times as difficult as the 'E' vanity.
1QLbz8	837,596,142
1aaaaa	15,318,045,009	Well after various pivots and subsequently more difficult.
1zzzzz	15,318,045,009
111111	1,099,511,627,776	A special case, leading numbers 1 (one) is especially difficult.

Use of vanitygen to try to attack addresses

Using vanitygen you might think that you would be able to find the private key for a given address. In practice, this is considered impossible. Given that the difficulty increases exponentially the longer your vanity is, so does the average time required to find that vanity. The example table below shows how an increasingly complex vanity affects the difficulty and average time required to find a match only for that vanity, let alone the full address, for a machine capable of looking through 1 million keys per second.

vanity	difficulty	average time
1B	22	< 1s
1Bi	1,330	< 1s
1Bit	77,178	< 1s
1Bitc	4,476,342 (4.48E+6)	< 10s
1Bitco	259,627,881 (2.6E+8)	3 minutes
1Bitcoi	15,058,417,127 (1.506E+10)	3 hours
1Bitcoin	8.7339E+11	1 week
1BitcoinE	5.0657E+13	1 year
1BitcoinEa	2.9381E+15	60 years
1BitcoinEat	1.7041E+17	3,500 years
1BitcoinEate	9.8837E+18	200,000 years
1BitcoinEater	5.7325E+20	11,700,000 years
1BitcoinEaterAddressDontSend	1.6209E+47	3.3E+33 or 3.3 decillion years.

See also

• Bitcoin Vanity Generation Website