For fun: the lowest block hash yet

[gmaxwell]

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

[e4xit]

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"?

[elgreco]

Update please 

[gmaxwell]

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.

[sile16]

What is the best block for litecoin?

[abcdefyyy]

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.

[abcdefyyy]

Currently, the highest achieved difficulty has block 266381:

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

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

[gmaxwell]

Currently, the highest achieved difficulty has block 266381:

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

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

See also: https://bitcointalk.org/index.php?topic=29675.msg3490536#msg3490536

[gmaxwell]

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.

[amaclin]

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

[teukon]

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?

[gmaxwell]

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]

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.

I see, thanks.

Interestingly, it seems to me that we should be "ahead" in this sense about 2/3 of the time.  I believe this follows from the fact that given some amount of work done, n say (number of hashes), the probability that we are behind at that point is simply (1 - 1/n)^n which converges to exp(-1) as n tends to infinity.

[TheRealSteve]

The current top 20 are:

Time for an update, as another thread was posted that basically asked the same thing

The current top 20 are:

height   hash                                                               note
334261   000000000000000000002d414bb8f9175ba6c6563721e1ba2c1373c2bd94f29f
336175   000000000000000000005a5e143087632fbf0eea743ad99646d9fc67d40f7441
331908   000000000000000000006836c4009ab00485cd1de4d5958ca7839184d0b80067
326055   000000000000000000007e1166d92acf81d4e2d95934fcdec1276b09a7db9390
343775   000000000000000000007eef13ee1f2fcf1b469bd862fcc93b48ec49548ecf6d
340483   000000000000000000008ac86ba28085be84af2ebd6fc6935a004e57fb60c083
313338   00000000000000000000b7de9e5c19e52be073156924b7cf235efb27ae8a202a
331987   00000000000000000000ec03e3183bacc8b18437180f63f6a563267a186225bc
334151   0000000000000000000119adb3da72742b1eba98f9dc26f73858e91652b42287
333904   0000000000000000000119f88871f8a3c3b7be053c98b31e9c4676df30243cfe
320736   0000000000000000000137130c5a047157e7b0e063de6f3d30246a4f2005a818
315024   0000000000000000000181f37629e8b80debca2c295c350cb1bd156e7e1a25ee
340600   00000000000000000001a092bb0f2311bf00987a8f7d92e2ed6b36a522054741
324204   00000000000000000001bdebf80d8c40d9b30a6fe76b962ff59c8d3cdeec3473
343641   000000000000000000020fc1ca1268a27de8646059ae2bcca61d13d16890b5db
326091   000000000000000000024b7dea2b63b4e2be64ef1663369fe2f22504587d094b
330140   000000000000000000026ccbc4bbb6a608e90132329190291127f971a604e5c9
266381   000000000000000000028c32e6952731326747bae4be8db0f832d6eea0362050   lowest block height
349240   00000000000000000002a133e4691d2f8894a3af7a1b3624e8c2e8c7a8a4fe3c   highest block height
330727   00000000000000000003107221e16ef91fdf83b3729c5f370dafb754bf6443b2

[TheRealSteve]

Just to poke at some of David Rabahy's trivia questions:

Is a hash of *all* 0s possible?

Current block with the most number of 0's (anywhere, not just leading) in the hash:

height   hash                                                               note
326799   000000000000000003fec4b5cd08090ab80010345952ab08048e088a00c2b09b   29/64* zeros

(* see earlier discussion on whether all zeros is even theoretically possible )

One wonders when a trailing triple 0 appears.

http://btc.blockr.io/block/info/9521 (actually four trailing zeros - other blocks with four trailing: 83373, 293374, 332802)
http://btc.blockr.io/block/info/10169 (actual triple)
( there's none with 5 trailing zeros )

Which hash has the most trailing 0s?

Tie between the above four listed

Why not a leading sequence of 3.1415926535...?

Can't have it leading, of course, but here's one with 314159 in it, at least (only one, thus also no longer sequence yet):

height   hash
234923   0000000000000171ae44bb6c1700314159dc61480b54edf71e5281ee7c6147a7


Here's some other fun ones

height   hash
132928   00000000000011eec4defc0ffee303401e460d2b8406474692d0ff141b9cbbf4
170852   00000000000002b58bf498d718db69dfc25cb318036949d3dad6bc0ffee28744
 57598   00000000051565707437c6626a8f88c92fe9decaf4c19f0c1b77558d3bf03aac
 84177   0000000000161062e2762c06457decaf0298724f662468465c84ff595abde159
137577   00000000000001e06f54fa79354e337678f840a7bc75ddecaf8fd9d089f9eed2
148781   00000000000004c2d5703896fb122b28dc7347f3023b0decaf28e3aacffffcb1
189433   00000000000005decafc4b33943d70fc596dd080f9a6737d94e9b4c88d890bf7
210406   00000000000002de9c1decaf9cb207af4452e8f00baeadc7729618ff3f4ce9e9
272206   00000000000000048d9564d82b8ac4d20decafb08e831ea7c8ddef7b9b5fac90
279275   00000000000000004ada6d6cead5c00a860494582252371c9c294decaf3b422a
303682   00000000000000005a9d3af33c5b4b52cc6b53c8decafc6dfb4259b06681dfaa
317717   000000000000000002e4c9274d83196ef16b0130972e7cc6ddecaf735cc67699
344465   000000000000000006c7cdecaf9dbe50a5fc693e7a555550d57aa1706f3f964b
344545   00000000000000000bbcc57dd86a829d674506e0cb151a09e91a9decafbf292e

No 'deadbeef'... yet.

[Mikestang]

Thanks for the update!

[Har01d]

There is a couple more...

 323453 | 000000000000000012345b434cea9b76ae6bffb49e624ca60182fc15a0a1ee2b
 155644 | 00000000000002ad18f02d363564da3501234596dae6345b93fa1579fc3f7d98
 218505 | 0000000000000141c1e370d4123456771e7d77463e91e4f2a5e572257ef46362

 321252 | 000000000000000010c1948fe886469b0e8d4f6aef7c2373abcdefe8fc9a2e86
 270096 | 0000000000000003606abfa5b19abcdefd839cc1b0da2fea63cbda317597de5a
 112974 | 000000000000b6e76dba167cc240c0014abcdef563ecd8ceec73f1ac57c6f420

and there is no "dead*beef" yet, but there is...

 18851 | 000000005a18c8f3b0c7a32159b76edcdc7af5bada903af00d60dd8fad297c0c

Have fun

[Taras]

Okay, but what about the highest block hash?
I'm predicting it to start with 00000000ffff.

[TheRealSteve]

Okay, but what about the highest block hash?

The current bottom 10 are:

height   hash                                                               note
32009   00000000fff9e01287736bee2fecdd88ae31b5602858c5273d43351cfadecd58   highest block height
 5386   00000000fff91949181449d048aca5a1cc6d0e3e3f34e89c00ab2709696b8da0
27948   00000000fff58158d6ce595a2976d547f16b0ec8aba64b7a9a68c78d469b54b5
31664   00000000fff3d56591bc0eae8cee73a214d1d451d704f86126415ed540850df7
30133   00000000fff31576873d6ec35ba6659e72193ddf621ea1edd7faa462336a2211
 1304   00000000fff0728c5da1548b4f15576aa272f0f4952031ae56a5be355310ba0a   lowest block height
31108   00000000ffeec57f29c3f3df6014774aa1a2f00114ab16bd26b0d270974cd706
 9396   00000000ffeb8e847d94f7085c6cc0359c77d8ebe52b9fb59b90e9ef95a23c44
16250   00000000ffeb2708cfc0aa1b5db3a6eacccc9112eb10cc0de2ec3e98c6c11a7a
28614   00000000ffe5255e229781dd72b1626c4df90e77390d38f6337ce949bc3ff300

I'm predicting it to start with 00000000ffff.

AMAZING!
but wrong :x

[Taras]

Okay, but what about the highest block hash?

The current bottom 10 are:

height   hash                                                               note
32009   00000000fff9e01287736bee2fecdd88ae31b5602858c5273d43351cfadecd58   highest block height
 5386   00000000fff91949181449d048aca5a1cc6d0e3e3f34e89c00ab2709696b8da0
27948   00000000fff58158d6ce595a2976d547f16b0ec8aba64b7a9a68c78d469b54b5
31664   00000000fff3d56591bc0eae8cee73a214d1d451d704f86126415ed540850df7
30133   00000000fff31576873d6ec35ba6659e72193ddf621ea1edd7faa462336a2211
 1304   00000000fff0728c5da1548b4f15576aa272f0f4952031ae56a5be355310ba0a   lowest block height
31108   00000000ffeec57f29c3f3df6014774aa1a2f00114ab16bd26b0d270974cd706
 9396   00000000ffeb8e847d94f7085c6cc0359c77d8ebe52b9fb59b90e9ef95a23c44
16250   00000000ffeb2708cfc0aa1b5db3a6eacccc9112eb10cc0de2ec3e98c6c11a7a
28614   00000000ffe5255e229781dd72b1626c4df90e77390d38f6337ce949bc3ff300

I'm predicting it to start with 00000000ffff.

AMAZING!
but wrong :x

Damn! My Big Gang Mafia intuition was wrong!

I wrote a chain parser myself but only did the first 10,000 blocks. (It can only see blk000000.dat)

What about the hashes with the most zeros anywhere in the hash?