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481  Alternate cryptocurrencies / Altcoin Discussion / Re: List of CPU Friendly AltCoins on: November 06, 2017, 07:10:26 AM
biblepay coin BBP is cpu mine coin.


Hard to say without any specification of the biblehash PoW.
What *exactly* is it computing?
482  Alternate cryptocurrencies / Altcoin Discussion / Re: Why nobody here talkin' about Grs and Vertcoin? on: November 04, 2017, 09:46:15 PM
Vertcoin current protocol (lyra2rev) seems to be ASIC resistant  for now.

No, it does not seem ASIC resistant. Its memory footprint is way too small:

Coin                    PoW Memory requirement in MB
Vertcoin               0.006 (poorly documented)
Litecoin                0.125
Monero                2
Ethereum             2048+

Of these, only Ethereum can be said to be seriously ASIC resistant.
Monero is only somewhat ASIC resistant.
483  Alternate cryptocurrencies / Altcoin Discussion / Re: Why nobody here talkin' about Grs and Vertcoin? on: November 04, 2017, 05:29:24 PM
true ASIC resistant coin like VTC

You mean wannabe ASIC resistant.
It's current PoW is rather ASIC friendly.
484  Alternate cryptocurrencies / Altcoin Discussion / Re: Looking for best ICO on: October 25, 2017, 07:06:03 PM
The best ICO is no ICO...
485  Bitcoin / Development & Technical Discussion / Re: Merkle Tree Proof evaluation - Itsuku algorithm proposal on: October 13, 2017, 07:29:34 AM
The beauty of MTP is that the miner allocates memory but not the verifier. However, the trade-off for that is the size of the proof.

Memory use by miners only, and not by verifiers, is common among asymmetric algorithms. Earlier ones,
like primecoin, Cuckoo Cycle, and Equihash do not require the big proofs that MTP requires, but only a
few hundred bytes.

Quote
Very cool and very interesting! I've always wondered why it never appears feasible to utilize a compression algorithm to shrink the size of the proof in this case, or compress data inside blocks in the case of btc.

I think the average data can be shrunk via compression is often by a factor of 1/3rd. From an amateur perspective, being able to fill roughly 3x the amount of data per size would seem to be a worthwhile approach. Especially as compression isn't particularly resource intensive, at least not in comparison to mining cryptographic functions. Adding a compression abstraction layer woudn't appear to bottleneck the process. But I would guess I'm missing some important point here as crypto engineers never seem to bother with compressing data?

Cryptographic data, such as hash outputs and elliptic curve points, look completely random and thus do not compress at all. These dominate the blockchain data, leaving only a small amount of compressibility in script bytecodes and counters and such.
486  Alternate cryptocurrencies / Mining (Altcoins) / Re: Monero ASIC next from Bitmain? on: September 24, 2017, 01:24:10 PM
Monero is memory intesive algo.

If Bitmain is able to create ASIC for memory intensive algo, probably they'll target ethereum (ethash) first

Coin                    PoW Memory requirement in MB
Litecoin                0.125
Monero                2
Ethereum             2048

All these are "memory hard". Guess which ones are easier to make ASICs for...
487  Bitcoin / Development & Technical Discussion / Re: Why would make the extra merkle commitment asicboost uneconomical? on: April 12, 2017, 02:26:25 PM
If one collects collisions on a central server (the most efficient way to find a lot of collisions in a big pool), one needs about 3 billion hashes to create 25 million 4-way collisions.  If one can live with 5 seconds delay (i.e. blocks miss some high-fee transactions from the last 5 seconds), one can  reduce this to 5 billion hashes in 5 seconds,

Your analysis appears correct. To elaborate on the math above:

Given x * 2^32 hashes, the probability of a k-way collision on a particular 32 bit value equals
choose(x * 2^32, k) * (2^-32)^k * (1 - 2^-32)^{x * 2^32 - k} which is about x^k/k! * e^-x.

For x=3/4 we get a fraction of 25M/4B 4-way collisions.
And for x=5/4 we get a fraction of 125M/4B 4-way collisions
(we actually get more than an extra quarter of that in useful collisions from k=5 and higher).
488  Alternate cryptocurrencies / Mining (Altcoins) / Re: Interested in CPU-mining? on: April 05, 2017, 04:25:59 PM
and verium is bad. it takes a long time to mine and the amount you get per block is tiny. Not really worth it from my 1 day experience

Time to mine is not the issue. The huge problem is needing 128MB just to verify a proof-of-work.
Proof verification is supposed to be very cheap, so this makes for a horrible PoW...
489  Bitcoin / Development & Technical Discussion / Re: Travelling salesman problem as a PoW algorithm? on: April 05, 2017, 02:21:54 PM
I'm just wondering if the Travelling salesman problem could be used as a PoW algorithm?

Sort of. If the salesman has to visit a small fixed number (e.g. 42) of cities in a huge random
bipartite graph, then Cuckoo Cycle https://github.com/tromp/cuckoo fits the bill...
490  Alternate cryptocurrencies / Tokens (Altcoins) / Re: [ANN] æternity blockchain ∞ GET AE TOKEN ∞ [PoS x PoW | Smart Contracts] on: April 03, 2017, 02:28:33 PM
The calculation of the AE is slightly off, fixing now.

That's not slightly off...

That's dividing by 1.1 instead of multiplying by 1.1 for the bonus...
491  Bitcoin / Project Development / Re: [ANN] Bitcoin PoW Upgrade Initiative on: March 23, 2017, 08:38:32 PM
I propose if you're going to change Bitcoin's proof-of-work to something other than the current SHA-2(56) to something else then you might as well go all in on SHA-3 to make it even more secure against near-future quantum computing technology (which governments may already have).

SHA-3 does that.

All SHA-3 candidates are rather ASIC-friendly, and Hashcash with such a hash function is highly
vulnerable to quantum speedup with Grover's algorithm.
492  Bitcoin / Development & Technical Discussion / Re: Cuckoo Cycle proof-of-work: $5000 in bounties on: March 20, 2017, 02:04:30 PM
There is a (v)movntdq(a) instruction (sse 4.1+ I think) that bypasses cache operations for faster mem writing if the data involved aren't going to be cached in any useful way. You might want to check whether it's useful for this case.

I spend most time updating random bits, which I access at word (32 bit) granularity.
I tried using the corresponding intrinsic _mm_stream_si32, but it is a 45% slowdown...
493  Bitcoin / Project Development / Re: [ANN] Bitcoin PoW Upgrade Initiative on: March 20, 2017, 04:01:24 AM
If anyone's interested Aeternity has a testnet running using Cuckoo Cycle https://github.com/aeternity/testnet

The testnet hasn't implemented Cuckoo Cycle yet; they're running some dummy PoW...
494  Alternate cryptocurrencies / Mining (Altcoins) / Re: Most ASIC resistant algo? on: March 20, 2017, 12:24:47 AM
A better question is: what is the most ASIC-resistant instantly verifiable proof-of-work algorithm?

PS: Some people call any PoW that doesn't have ASICs available ASIC-resistant.
      That is clearly not what ASIC-resistant means. It means that it's questionable
      whether whether the efficiency gained (e.g. in hashes per Joule) is enough to
      compensate for the research, development and production of said ASICs.
495  Alternate cryptocurrencies / Mining (Altcoins) / Re: Zcash/Zclassic/Equihash GPU Benchmarks on: March 11, 2017, 05:38:31 PM
As you can guess from the title, I've made a benchmark list for Equihash. I've gathered info from bitcointalk and the Zcash/Zclassic chats/forums. The list is not yet complete (it will most likely never be since the miners get updated so often and plenty of new cards are coming up this year).

Much of the data is being hard to get without first hand experience but I managed to gather some, this is the list at the moment: https://zdeveloper.org/wiki:zcash_mining_benchmarks
I'm waiting for corrections and updates. Maybe it will helps some people decide which cards to get next time they assemble a rig.  Smiley

Most power efficient (Sol/Joule) cards:

AMD        RX480   Sapphire Nitro+ OC   8GB   305/140 = 2.2
NVIDIA    GTX 1070   -                           8GB   450/100 = 4.5

Shockingly, Nvidia is more than twice as efficient...
496  Bitcoin / Development & Technical Discussion / Re: Moving towards user activated soft fork activation on: March 05, 2017, 03:56:45 AM
I understand that the miners don't want the lighting networks and I understand why - because it goes against their interests.

They perceive it as going against their interests. But this perception appears flawed.

Bitcoin needs scaling improvements like lightning in order to thrive in the long term.
A non-scalable bitcoin will ultimately be overtaken by a better-scalable competitor.

497  Bitcoin / Development & Technical Discussion / Re: Cuckoo Cycle proof-of-work: $5000 in bounties on: March 05, 2017, 03:30:36 AM
the recent boost in bitcoin value allows me to increase the bounties by 50%:
This seems to imply you are holding your bounties in bitcoin.
Since this is targeted at the bitcoin community, I assume you are also paying them in bitcoin.
Why, then, do you advertise the bounty amounts in dollars instead of in bitcoins?

Two reasons:
1) I want to limit my financial liability, and if people keep claiming bounties while bitcoin explodes in value, I might need to buy bitcoin at exorbitant prices.
2) I thought the dollar amounts sound more impressive:-)

But, on request, and while supplies last, I'd be happy to make a payout in bitcoin.
498  Bitcoin / Development & Technical Discussion / Re: Cuckoo Cycle proof-of-work: $5000 in bounties on: March 05, 2017, 03:26:51 AM
I tried to compile this but failed due to non avx2 use, so it did compile some of the files... so I run cuckoo28:

perf stat -d -d -d ./cuckoo28

Further perf stats indicate a lot of overhead here (the cmpxchg stalls the jump?): http://imgur.com/a/zwEmP
(data obtained by running perf top while ./cuckoo28 was running).

Given that this was on a single thread, couldn't this be done with plain unlocked moves? Also, in multithreaded applications, would it be possible to gamble faster unlocked moves trading data accuracy in order to produce a faster version with possible data corruption?

Indeed, for single threaded use (-t 1, which is the default) one should run the singlethreaded
./cuckoo28st instead. That one doesn't use atomic updates like the cmpxchg.

For multi-threaded use, increasing the number of threads also increases the likelihood of overlooking cycles
due to data-races. It's not clear though at how many threads the use of atomics becomes well-advised.
499  Alternate cryptocurrencies / Marketplace (Altcoins) / Cuckoo Cycle proof-of-work: $15000 in bounties on: March 03, 2017, 09:41:35 PM
Cuckoo Cycle is an instantly verifiable memory bound Proof-of-Work,
whose run time is dominated by memory latency.

I invite anyone to try claim one of the following bounties
(backed by the Cuckoo Cycle Bounty Fund)
for improving my C++/CUDA solvers:

performance improvement   4x           2x           sqrt(2)x
CPU                                    $6000     $3000     $1500
TMTO                                  $6000     $3000     $1500
GPU                                    $3000     $1500     $ 750

Details at

https://github.com/tromp/cuckoo

Happy bounty hunting...
500  Bitcoin / Development & Technical Discussion / Re: Cuckoo Cycle proof-of-work: $5000 in bounties on: March 03, 2017, 09:31:04 PM
Since the bounties are (partially) backed by bitcoin in the Cuckoo Cycle Bounty Fund,
the recent boost in bitcoin value allows me to increase the bounties by 50%:

performance improvement   4x           2x           sqrt(2)x
CPU                                    $6000     $3000     $1500
TMTO                                  $6000     $3000     $1500
GPU                                    $3000     $1500     $ 750

Happy bounty hunting...
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