For fun: the lowest block hash yet - page 3.

gmaxwell

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Quote from: teukon on August 01, 2014, 02:15:38 PM

Oh, nice!
May I ask how you are calculating/estimating the total work done by the network?

The smallest block hash yet found is an estimate of the total work done by the network. Also, the sum of the difficulties (well *2^32) on the blocks so far is an estimate, which is the one returned in the bitcoin core logs or in the getblockchaininfo rpc.

teukon

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Quote from: gmaxwell on August 01, 2014, 02:30:35 AM

00000000000000000000b7de9e5c19e52be073156924b7cf235efb27ae8a202a

math.log((2**256)/0x00000000000000000000b7de9e5c19e52be073156924b7cf235efb27ae8a202a,2) = 80.47746080768307

"Apparent difficulty" of 391,895,084,984,304.

And pretty much just on track with the regular block measured work: UpdateTip: new best=00000000000000000000b7de9e5c19e52be073156924b7cf235efb27ae8a202a height=313338 log2_work=79.978295 tx=43580048 date=2014-07-31 13:29:05 progress=0.999999

This is the first block solution we've found which is a >80 bit partial preimage of 0.

Oh, nice!

May I ask how you are calculating/estimating the total work done by the network?

amaclin

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We should start "Guinness facts for Bitcoin" project with an answers to all popular (and even dumb) questions

1. What is the lowest block hash seen?
2. What is the maximum tx (in bytes, in funds, in fees)
3. What is the longest scriptPub and scriptSig?
4. How many zeros does your publicKey have in hex representation?
5. The first and last (alphabet order) address (need signature verifying)
6. Maximum transactions count in block
... etc

gmaxwell

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Activity: 4284

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00000000000000000000b7de9e5c19e52be073156924b7cf235efb27ae8a202a

math.log((2**256)/0x00000000000000000000b7de9e5c19e52be073156924b7cf235efb27ae8a202a,2) = 80.47746080768307

"Apparent difficulty" of 391,895,084,984,304.

And pretty much just on track with the regular block measured work: UpdateTip: new best=00000000000000000000b7de9e5c19e52be073156924b7cf235efb27ae8a202a height=313338 log2_work=79.978295 tx=43580048 date=2014-07-31 13:29:05 progress=0.999999

This is the first block solution we've found which is a >80 bit partial preimage of 0.

gmaxwell

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Activity: 4284

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Quote from: abcdefyyy on July 06, 2014, 04:20:27 PM

Currently, the highest achieved difficulty has block 266381:

https://blockchain.info/block/000000000000000000028c32e6952731326747bae4be8db0f832d6eea0362050

Achieved difficulty: 110,484,089,548,580

See also: https://bitcointalksearch.org/topic/m.3490536

abcdefyyy

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Currently, the highest achieved difficulty has block 266381:

https://blockchain.info/block/000000000000000000028c32e6952731326747bae4be8db0f832d6eea0362050

Achieved difficulty: 110,484,089,548,580

abcdefyyy

newbie

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Ok, I scan the blockchain in python and calculated the achieved difficulty for each block.

If anyone is interested I can put the data here.

Interesting thing is that the block 0 (genesis block) have achieved difficulty equal to 2536.

sile16

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What is the best block for litecoin?

gmaxwell

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Activity: 4284

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Not too much has happened, I was waiting to get one with apparent work > 2^80 to update again.

Best right now is 0x000000000000000000049bb3b6b9c135f66536e066704369905043df809c2441 ... or about 2^77.79, the cumulative block measured work level on the network is at 2^79.3 so we're behind.

elgreco

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Update please

e4xit

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Quote from: gmaxwell on November 06, 2013, 10:13:24 PM

Really the network has only done about 73.6 bits of work so far, our lowest is lucky.

Statistically, as the block hashes (I assume) form some kind of distribution, I would say in laymans terms, that we are likely within the 73.6 bits of work done so far to have some outliers or 'lucky' results.

My question would therefore be, would the amount of 'luck' required for our lowest yet fall outside the expected distribuition (and therefore be truely 'lucky') or is this "expected luck"?

gmaxwell

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Really the network has only done about 73.6 bits of work so far, our lowest is lucky.

David Rabahy

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Quote from: hahahafr on November 06, 2013, 05:58:52 PM

This basically mean that brute-forcing something of 78.65 bits (80 almost) is possible?

Um, short of (getting all of that computing power to cooperate to brute-force attack is unlikely in the extreme) but even 78.65 bits (rounding up to 80 is not reasonable; it is over 2.5x harder) is a very long way from 160. Whatever computing power it took to get to this 78.65 bit result is 81.35 bits short, i.e. over 3 billion trillion times. If you can gather even 1/65536th of it I'd be stunned but that would put you at 62.65 bits, i.e. over 200 trillion trillion times short. Spend your energy pursuing something a little more likely to bear fruit.

hahahafr

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Quote from: gmaxwell on November 05, 2013, 12:39:41 PM

2013-10-27 14:55:42 SetBestChain: new best=000000000000000000028c32e6952731326747bae4be8db0f832d6eea0362050 height=266381 log2_work=73.237967 tx=26093998 date=2013-10-27 14:49:44 progress=0.999972

In [592]: math.log((2**256)/0x000000000000000000028c32e6952731326747bae4be8db0f832d6eea0362050,2) Out[592]: 78.65083195521588

This basically mean that brute-forcing something of 78.65 bits (80 almost) is possible?

kjj

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Quote from: Ecurb123 on November 05, 2013, 01:22:28 PM

Quote from: etotheipi on July 17, 2011, 09:53:26 AM

Since I finally figured out how to read the block chain...

How did you figure out how to read the block chain? can you recommend any sites?

It is like that scene in the Matrix. Just set your terminal to green and let it scroll by for a while. After a while you'll be able to just "see" things.

Ecurb123

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Quote from: etotheipi on July 17, 2011, 09:53:26 AM

Since I finally figured out how to read the block chain, I decided it would be fun to find the lowest hash produced, yet. The hash for a block doesn't have to be AT that difficulty, it just has to beat it, and I figured there's gotta be some blocks with major overkill in terms target hash, just by luck. Well here it is, block 125,552:

http://blockexplorer.com/block/00000000000000001e8d6829a8a21adc5d38d0a473b144b6765798e61f98bd1d

If I did the difficulty calculation correctly (no guarantees), I believe this block would've been valid even at difficulty 35,987,768,035 (current difficulty is 1,564,057). Can someone verify that?

How did you figure out how to read the block chain? can you recommend any sites?

gmaxwell

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Activity: 4284

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2013-10-27 14:55:42 SetBestChain: new best=000000000000000000028c32e6952731326747bae4be8db0f832d6eea0362050 height=266381 log2_work=73.237967 tx=26093998 date=2013-10-27 14:49:44 progress=0.999972

In [592]: math.log((2**256)/0x000000000000000000028c32e6952731326747bae4be8db0f832d6eea0362050,2) Out[592]: 78.65083195521588

gmaxwell

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Activity: 4284

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2013-09-16 06:36:03 SetBestChain: new best=0000000000000000004bb6e7e2661661ba9809062d90c3121933d6d02c8bd763 height=258283 log2_work=71.955296 tx=23869863 date=2013-09-16 06:35:37 progress=0.999997

We're pretty lucky now with a 73.75 bit solution on 71.95 in effort. Tongue

David Rabahy

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N trailing 0's should appear with an average of 1:2^(4N).

N 0's anywhere in 64 hexdigits is 1:2^(4N-6).

Excluding the leading 0's cuts into our odds.

TierNolan

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Quote from: David Rabahy on September 09, 2013, 02:05:31 PM

The Block 2162 hash 00000000aaf0ab905dcdd85a8aac5bfff33b22211222bcdf94b571c00d93d999 is loaded with triples; F's, 2's, 2's again, and 9's (trailing) but still the trailing triple 0's eludes us.

Three zeros should happen once every 4096 blocks on average, so there should be loads.

Topic: For fun: the lowest block hash yet - page 3. (Read 21275 times)