Random Number On Blockchain - page 2.

etherflip

copper member

Activity: 103

Merit: 7

Quote from: spartacusrex on January 24, 2018, 12:22:29 PM

Take the first bit of Hash(blockhash) of the last 64 blocks.

Make a 64 bit number. Hash That.

It's random.

Everyone can calculate it independently.

This is not truly random. There is a reason random.org relies on lightning strikes to generate random numbers.

If you are using Ethereum, Oraclize provides RNG via ledger and access to sites like random.org - we are using Oraclize.

DrSha

jr. member

Activity: 42

Merit: 4

<3 BTC

https://bitcointalksearch.org/topic/using-sha512-hash-as-random-number-generator-for-gambling-services-77206

This might be a good reference point for you to check out.

Taras

legendary

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Please do not PM me loan requests!

Quote from: truedeckTeam on February 06, 2018, 07:01:36 AM

Thanks but if I use block hashes, then it will be pre predictable. I need something that is unpredictable until it gets in public.

The last digit of a block hash is really not pre-predictable because no miner in their right mind would forfeit their block in order to manipulate the last digit. The benefit of doing so would have to be greater than the 12.5 BTC loss of throwing away their solution. It may still be possible to manipulate if there are two block candidates (an unresolved chain split) but the usual waiting for 6 confirmations solves that.

truedeckTeam

jr. member

Activity: 42

Merit: 1

Thanks but if I use block hashes, then it will be pre predictable. I need something that is unpredictable until it gets in public.

CounterEntropy

full member

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Quote from: truedeckTeam on January 24, 2018, 12:05:54 PM

How Can one generate a random number on blockchain , and all remain decentralised , everyone has same result but no one know the number until the number disclose to public.

Read: How random the last digit of a block hash really is?

Colorblind

member

Activity: 392

Merit: 41

This text is irrelevant

Quote from: RGBKey on January 26, 2018, 12:52:55 PM

I've struggled with a problem like this before. I was trying to find a way to use the Bitcoin blockchain to generate random numbers similar to how provably fair gambling sites generate them now. Unfortunately, I couldn't find a way that didn't involve either waiting time for the next Bitcoin block (which was undesirable for me) or placing trust in another party.

You can’t generate another random number before another piece of information added to what you use as a seed, therefore you can’t really generate numbers more often than new block appears. You may however generate arbitrary amounts of random numbers per block or use faster blockchain to Do so.

RGBKey

hero member

Activity: 854

Merit: 658

rgbkey.github.io/pgp.txt

I've struggled with a problem like this before. I was trying to find a way to use the Bitcoin blockchain to generate random numbers similar to how provably fair gambling sites generate them now. Unfortunately, I couldn't find a way that didn't involve either waiting time for the next Bitcoin block (which was undesirable for me) or placing trust in another party.

Colorblind

member

Activity: 392

Merit: 41

This text is irrelevant

Yeah this is pretty much comes from irreversibility (unpredictability) of hash function.
All you need to do is to take some immutable properties, that being added to blockchain unpredictable (as spartacusrex mentioned above) and use hash to further normalize distribution and you got it. Just write a rule that works similar every time next block is appended.

It is important to understand that this still won't be "true" randomness (if such thing even exists), but will be nearly impossible to predict and likely give uniform distribution of output values.

spartacusrex

hero member

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Take the first bit of Hash(blockhash) of the last 64 blocks.

Make a 64 bit number. Hash That.

It's random.

Everyone can calculate it independently.

truedeckTeam

jr. member

Activity: 42

Merit: 1

How Can one generate a random number on blockchain , and all remain decentralised , everyone has same result but no one know the number until the number disclose to public.

Topic: Random Number On Blockchain - page 2. (Read 785 times)