VanitySearch (Yet another address prefix finder) - page 23.

gmaxwell

staff

Activity: 4326

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Quote from: bigvito19 on October 26, 2020, 05:42:34 AM

So its kind of pointless to try to find a address with this if you don't know seed. What exactly is the search space when searching with vanitysearch is it 2^160 or 2^96?

The search space is 2^256, though some keys map to the same addresses. The non-uniformity means that some keys are more likely than others in your search, but all are still possible..

If you were searching for keys beginning with B and the first letter of the set of keys matched in this pattern [..B...B..............B....B.............B....BB.B..BBB] the probability of selecting that last B would be 1 in 54 (because only 1 in 54 starting positions will select it) while it would be 14 out of 54 for the 5th one (because 14 different starting positions will end up there).

But on the real (enormous) range this doesn't really matter... it's just a pedantic detail.

MrFreeDragon

sr. member

Activity: 443

Merit: 350

Quote from: bigvito19 on October 26, 2020, 05:42:34 AM

Quote from: gmaxwell on October 25, 2020, 10:13:14 AM

Quote from: xhomerx10 on October 25, 2020, 08:43:59 AM

Vanitysearch starts with a seed which, if not specified by the user, is generated randomly. It proceeds from there searching sequentially. If you use the same seed, you will get the same results.

It's perfectly secure to do this. Searching this way creates an infinitesimal bias in the keys that are selected (the selected key is more likely to be found after a long run of non-matches than after an immediately prior match) but even where an attacker knows the exact prefix searched for the bias is extremely tiny-- because nearly spaced solutions are extremely unlikely to begin with-- and not exploitable (because you can't search only keys that meet that criteria... since the criteria itself requires generating the pubkeys to check).

So its kind of pointless to try to find a address with this if you don't know seed. What exactly is the search space when searching with vanitysearch is it 2^160 or 2^96?

Vanitysearch starts from the start key(generated based on seed or selected randomly) and then increment it by 1. So, technically there is no limit of the range 2^160 or 2^96, the tool will work till you not stop it.

Imagine the whole private key range from 0 to order (close to 2^256) and the start key marked as s somewhere between 0 and order.

Code:

[0] ......................... s ........................................................ [order]

Even s is very close to the order, it will continue work since the beginning, cause all the private keys are considered by modulo. It is like the infinite loop - while reach the order, start from the beginning.

So, my understanding is that search space is not limited in vanitysearch. It just increments the private key to check by 1 and stop when you stop it (or find the desired address if you select that option)

bigvito19

full member

Activity: 706

Merit: 111

Quote from: gmaxwell on October 25, 2020, 10:13:14 AM

Quote from: xhomerx10 on October 25, 2020, 08:43:59 AM

Vanitysearch starts with a seed which, if not specified by the user, is generated randomly. It proceeds from there searching sequentially. If you use the same seed, you will get the same results.

It's perfectly secure to do this. Searching this way creates an infinitesimal bias in the keys that are selected (the selected key is more likely to be found after a long run of non-matches than after an immediately prior match) but even where an attacker knows the exact prefix searched for the bias is extremely tiny-- because nearly spaced solutions are extremely unlikely to begin with-- and not exploitable (because you can't search only keys that meet that criteria... since the criteria itself requires generating the pubkeys to check).

So its kind of pointless to try to find a address with this if you don't know seed. What exactly is the search space when searching with vanitysearch is it 2^160 or 2^96?

gmaxwell

staff

Activity: 4326

Merit: 8951

Quote from: xhomerx10 on October 25, 2020, 08:43:59 AM

Vanitysearch starts with a seed which, if not specified by the user, is generated randomly. It proceeds from there searching sequentially. If you use the same seed, you will get the same results.

It's perfectly secure to do this. Searching this way creates an infinitesimal bias in the keys that are selected (the selected key is more likely to be found after a long run of non-matches than after an immediately prior match) but even where an attacker knows the exact prefix searched for the bias is extremely tiny-- because nearly spaced solutions are extremely unlikely to begin with-- and not exploitable (because you can't search only keys that meet that criteria... since the criteria itself requires generating the pubkeys to check).

xhomerx10

legendary

Activity: 3808

Merit: 7912

Quote from: ?? on ??

Does the video card also give random keys or sequential ones?

the point is not in the similarity of addresses, but in the nature of their generation. Vanity generates randomly, so it is safe, and Bitcrack generates sequentially, so it is very easy to repeat the generation of the same address any number of times

and in the opposite direction, on the contrary, it is easier to get accidentally into the key because sequentially it is unrealistic, the universe is too big https://bitcointalksearch.org/topic/m.55448862

Vanitysearch starts with a seed which, if not specified by the user, is generated randomly. It proceeds from there searching sequentially. If you use the same seed, you will get the same results.

nc50lc

legendary

Activity: 2646

Merit: 6681

Self-proclaimed Genius

Quote from: ?? on ??

yes, people who create a beautiful address using Bitcrack are very risky

Who'll do that anyways, it's not designed nor advertised to make vanity addresses Tongue

BitCrack is for "bitcracking" addresses' private keys which are purposely generated to be weak.
Like the puzzle transaction (unofficial thread) for example.
BTW, some of those are the private keys with balance that LBC had found over the years.

TryNinja

legendary

Activity: 2758

Merit: 6830

Quote from: blue Snow on October 24, 2020, 08:48:43 PM

why windows always deleting that file? and how to protect it from the defender?

Ideally, you would move away from Windows. Cheesy

But you can also whitelist their software on the Windows Defender: Add an exclusion to Windows Security

blue Snow

legendary

Activity: 1526

Merit: 1032

Up to 300% + 200 FS deposit bonuses

Windows 10 always deleting VanitySearch.exe (0 kb) every restart. I have to redownload again and again.

why windows always deleting that file? and how to protect it from the defender?

bigvito19

full member

Activity: 706

Merit: 111

Quote from: ?? on ??

does it not calculate private keys? Is it not possible to select from the list of addresses?

No, that program as is, you can't modify or do anything else with it.

ymgve2

full member

Activity: 162

Merit: 230

Quote from: ?? on ??

why the speed is low, it takes two days for this program to find 8 characters 40 bit, but Pairgen takes 5 seconds

https://github.com/basil00/pairgen/releases

That program is for finding two "similar" BTC addresses, like 53e1f4f491509f9012bd901be5147447f770018b and 53e1f4f491509f9012bd825ce1e9599b253188ef, which is completely different from creating a BTC address with a prefix that you specify.

It is fast because you have no control over what the matching part will be since it uses https://en.wikipedia.org/wiki/Birthday_attack

NotATether

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bitcoincleanup.com / bitmixlist.org

Quote from: ?? on ??

You've been warned, checking an address on list of address doesn't have O(1) complexity.

I don't understand what this means

He means it's not going to take 1 second/millisecond/microsecond to check one address, it could take 28,000,000 time units to check one address which is linear time, it could also take 28,000,000^2 time units - quadratic time, to check a single address, or it could take cubic time, you get the idea. The amount of time it takes depends entirely on the algorithm Jean_Luc is using to check the addresses. I haven't studied the code so I don't know which running time it'll take.

The idea is if you run a computation several thousand times, the time complexity of the algorithm makes a huge difference. An algorithm running in cubic time might never finish doing 28,000,000 runs, but quadratic time might finish that size.

Quote from: ?? on ??

only the CPU has a chance because the addresses were created on the CPU, you can wait for the same thermal noise that Intel uses as a source of entropy. But the video card will not be able to find the key because the addresses were created on the CPU, and the probability of a random match is negligible.

This assumes that the random number generator on Intel hardware can be programmed to use the same seed, which it can't. Since the seed comes from thermal noise, two Intel processors will never have the same entropy.

Even if vanity generators used Xorshift software RNG that you can set the seed of, vanitysearch can't export the seed that it used. That isn't implemented.

bigvito19

full member

Activity: 706

Merit: 111

Quote from: ?? on ??

only the CPU has a chance because the addresses were created on the CPU, you can wait for the same thermal noise that Intel uses as a source of entropy. But the video card will not be able to find the key because the addresses were created on the CPU, and the probability of a random match is negligible. For this reason, the pool LBC finds an addresses, it uses processors, otherwise it would not be possible https://lbc.cryptoguru.org/trophies

An example:
We have a hardware capable of generating 1GKey/s and we have an input list of 106 addresses, the following table shows the probability of finding a collision after a certain amount of time:

Time   Probability
1 second   6.8e-34
1 minute   4e-32
1 hour   2.4e-30
1 day   5.9e-29
1 year   2.1e-26
10 years   2.1e-25
1000 years   2.1e-23
Age of earth   8.64e-17
Age of universe   2.8e-16 (much less than winning at the lottery)

LBC generates keys in incremental mode starting from key 1, so it won't find no more collisions really it stop at bit 54 and the same goes with bitcrack too.

PawGo

legendary

Activity: 952

Merit: 1386

Quote from: ?? on ??

You've been warned, checking an address on list of address doesn't have O(1) complexity.

I don't understand what this means

https://en.wikipedia.org/wiki/Time_complexity

nc50lc

legendary

Activity: 2646

Merit: 6681

Self-proclaimed Genius

Quote from: alevlaslo on October 18, 2020, 08:29:54 AM

is there a 1-day probability of CPU detecting a private key for the full address, or is it zero?
-snip-

It's in the image: half of the search space in 6.31275e+33 years, that's equivalent to 6,312,750,000,000,000,000,000,000,000,000,000 x 2 years.
But since you insist that "it's the same as a lottery" in the deleted thread, you can try and no one will hold you back.

alevlaslo

hero member

Activity: 1988

Merit: 593

thank you, but the speed is 2 times lower

but the probability is higher by 580 thousand times

I deleted all addresses of less than 50 bitcoins, there are 47,000 addresses left, with them the speed drop is only 10%

addresses with less than 50 bitcoins unethical to attack, people's savings there are

bigvito19

full member

Activity: 706

Merit: 111

Quote from: alevlaslo on October 18, 2020, 09:39:37 AM

Core i5 4t
Vanytygen64 - 550 kkeys per second
Vanitysearch - 5 mkeys per second

how can I import 580,000 addresses to check at the same time, will it slow down the speed?

Use the -i inputfile

alevlaslo

hero member

Activity: 1988

Merit: 593

Core i5 4t
Vanytygen64 - 550 kkeys per second
Vanitysearch - 5 mkeys per second

how can I import 580,000 addresses to check at the same time, will it slow down the speed?

alevlaslo

hero member

Activity: 1988

Merit: 593

is there a 1-day probability of CPU detecting a private key for the full address, or is it zero?

this address was used by scammers to steal bitcoins from the exchange

alevlaslo

hero member

Activity: 1988

Merit: 593

Radeon VII how many MKeys?

bitcoinunide

newbie

Activity: 17

Merit: 38

Thank you @Jean_Luc for the Code!

We've created a browser tool, for non technical users, that they can easy merge split keys offline in their browser client!

https://github.com/sashmaaan/VanityAddressMerger

Topic: VanitySearch (Yet another address prefix finder) - page 23. (Read 33086 times)