Eventually, yes.  But you need to know how the standard client works. It follows the longest, valid, chain.  So lets assume you are evil miner 1. You have a significant amount of hashing power, say 10% of the network.   One in every 10 blocks is yours.

Statistically, in this case, you're mining one block every 150 seconds.  But that's just statistically.  You will quite regularly, mine 3 coins in a row. You can re-write your miner to NOT follow the longest valid chain. You can tell it to keep persevering with your chain until you're 4 blocks behind the rest of the network, before you abandon your tree.

And when you DO get those 4 coins, suddenly the chain you're on is the longest chain, and you've just invalidated (orphaned) those 4 blocks that other people mined (and, whoops, those were confirmed by the network, too!) and you've just done a very small, but very easy, 'traditional' 51% attack with only 10%. Consider it brains vs brawn.

There are other things you can do, too. You can just ignore blocks mined by other people, too. Let your miners run for an extra 5 seconds on that block before you switch to the next one. See if you can get a block too. Keep mining that one. If you're lucky, you'll beat the other chain, and orphan them.

It also helps (as in, helps nasty-miner-1) other miners having slower nodes, too. At the moment, it can take up to 15 seconds for a block to propagate throughout the BTC network. I haven't done any timings on LTC, but I assume it would be roughly the same. Having a fast, central, node, means you can be an entire block in front of everyone else.

Oh look, I'm doing BTC-hacking 101 in this thread.   Most of these issues are dealt with (by BTC and LTC) by having slower block times, and longer confirmations. As I said originally: Randomly changing numbers without knowing what the numbers are for is just a dumb idea.

I couldn't see anywhere that had already published a list of the 'lucky' blocks, so here they are.

1000 Coin reward will be paid on these blocks (from current to 200,000)
  26986 51736 74007 79466 87794 91460 130379 146205 169141 172008 194202 195147 198888

150 coin reward will be paid on these blocks (up to block 100,000):

24982 25032 25163 25230 25297 25346 25412 25435 25491 25511 25613 25951 25962 25968 25974 25990 26270 26302 26357 26489 26615 26624 27040 27066 27409 27458 27677 27910 27963 28008 28068 28166 28325 28436 28546 28639 28729 28940 29014 29240 29335 29371 29509 29620 29711 29748 30024 30042 30061 30184 30256 30274 30532 30533 30578 30584 30823 30908 30914 30928 30981 31048 31063 31090 31219 31392 31527 31530 31585 31590 31859 31980 32135 32204 32260 32340 32417 32465 32588 32653 32754 32839 33038 33078 33088 33181 33481 33665 33762 33780 33817 34084 34120 34228 34309 34316 34406 34597 34632 34669 34924 35068 35078 35231 35342 35403 35533 35613 35690 35767 35785 35826 35875 35884 35895 35908 35969 35985 36016 36275 36299 36315 36341 36365 36396 36409 36488 36597 36616 36755 36831 36860 36878 36950 37050 37310 37443 37655 37708 37727 37730 37762 37875 38049 38060 38061 38077 38090 38095 38140 38300 38494 38562 38579 38670 38944 39049 39157 39196 39230 39330 39387 39464 39470 39509 39754 39796 39873 40200 40332 40388 40403 40684 40703 40858 40895 41115 41272 41633 41731 41781 41838 41906 41998 42095 42211 42478 42538 42580 42608 42668 42698 42721 42737 42787 42804 43104 43523 43557 43771 43939 43943 43947 44063 44079 44153 44339 44542 44582 44667 44785 44869 44896 44939 45021 45022 45033 45099 45168 45472 45494 45547 45695 45903 46106 46315 46321 46466 46568 46739 46865 46962 47099 47125 47245 47267 47365 47468 47558 47638 47774 47781 47923 48025 48071 48219 48314 48521 48806 48854 49068 49093 49114 49333 49392 49530 49535 49538 49556 49559 49578 49725 49728 49780 49869 50450 50486 50616 50748 50839 50841 50866 50895 50932 50977 50990 51122 51180 51258 51482 51517 51709 51730 51859 51952 52007 52048 52055 52184 52332 52475 52489 52755 52872 53237 53288 53317 53365 53466 53614 53636 53732 54312 54386 54433 54765 54983 55131 55255 55282 55323 55630 55859 56126 56337 56550 56613 56763 56825 56866 56981 57017 57063 57099 57104 57166 57256 57307 57373 57514 57590 57815 57855 57893 57993 58150 58231 58269 58437 58640 58883 58885 58970 59085 59153 59445 59543 59557 59629 59637 59792 59830 59899 59998 60156 60170 60174 60359 60360 60362 60365 60417 61023 61070 61076 61081 61094 61225 61228 61251 61256 61388 61594 61694 61726 61848 61866 61891 61930 62015 62139 62165 62284 62368 62482 62662 62798 62811 62867 62983 63030 63105 63143 63182 63266 63309 63371 63634 63768 63872 64045 64141 64293 64362 64525 64600 64810 64865 64933 64949 65317 65400 65524 65632 65717 65819 65835 65995 66102 66163 66274 66294 66500 66865 67010 67033 67064 67189 67202 67334 67448 67451 67531 67608 67609 67615 67623 67785 67807 67834 68010 68207 68391 68552 68557 68896 69020 69063 69073 69085 69130 69195 69304 69453 69550 69681 69684 69880 70039 70064 70216 70286 70763 71216 71243 71350 71443 71571 71656 71760 71890 72229 72262 72541 72585 72648 72756 72826 72925 72985 73124 73175 73280 73370 73389 73530 73608 73613 73650 73798 73860 73886 73895 74040 74052 74149 74171 74305 74325 74400 74409 74571 74666 74693 74798 75014 75068 75136 75308 75328 75331 75433 75524 75642 75709 75850 76032 76058 76139 76237 76274 76435 76730 77041 77112 77166 77251 77355 77375 77420 77585 77608 78130 78274 78290 78361 78417 78475 78510 78579 78641 78949 78986 79478 79517 79525 79621 79643 79741 79882 79954 80030 80167 80362 80514 80561 80754 80790 80898 81632 81633 81692 81850 81859 81915 81976 81993 82011 82119 82448 82560 82654 82727 82793 82910 82961 83001 83050 83052 83054 83056 83185 83228 83671 83747 83889 84416 84474 84658 84678 84737 84833 84894 85123 85146 85238 85395 85445 85470 85503 85697 85766 85798 85891 86113 86128 86149 86280 86290 86456 86484 86593 86613 86639 86763 86924 86933 86945 87222 87655 87690 87790 87893 87962 88089 88250 88260 88276 88298 88305 88418 88567 88796 88876 88914 88967 89099 89112 89206 89230 89270 89384 89397 89419 89444 89663 89807 89900 89904 89963 90131 90214 90316 90622 90691 91041 91228 91402 91465 91477 91502 91522 91753 91916 92352 92431 92452 92582 92685 92764 92836 92878 92897 92935 92982 93023 93190 93259 93293 93385 93411 93508 93551 93578 93861 94558 94646 94767 94871 94942 94973 95204 95300 95349 95404 95409 95594 95599 95676 95761 95782 95785 95878 95888 95933 95956 96182 96252 96371 96991 97096 97933 97963 97998 98014 98180 98206 98235 98382 98569 98638 98808 98939 98966 98983 99081 99088 99160 99164 99237 99305 99319 99389 99397 99470 99486 99641 99677 99821 99912 99921 99924 99933

For anyone who cares, at the current block of 540605, it's 5. It changed from 4 at 524423

And picking a random coin that was released today - elacoin.

I happened to be watching the logs and I saw the block chain from 4443 through to 4515 (from 09:00:44 through to 09:02:37) switch to a longer chain. That's almost twice your confirmation period (4 blocks), and that was on a lightly loaded network.

And then, between blocks 5027 and 5100, two miners were fighting over the chain. It kept switching backwards and forwards.

+1  

OMG, Seriously, people are just randomly changing numbers without knowing WHY those numbers should be what they are.

15 seconds isn't going to be enough for blocks to get from one side of the network to the other. A couple of miners are going to modify their clients to ignore other chains, and just mine everything themselves. With blocks only 15 seconds apart, it's going to be almost impossible to avoid multiple, simultaneous, attacks on the coin.

Pools are going to need to know what N is, so they can calculate and verify shares. AFAIK, there's no method of exposing this from the client.

So, each time N changes, pools are going to have to shut down, re-write their verification code, and start back up again.

Basically: You're stuck with solo mining.

Guys. The correct way to do this is to

  1: Mine the seed block.
  2: Release the source code, and let binaries be created if you can't do it yourself
  3: Get the network up
  4: THEN release the seed block.

This is not rocket science.

Protip for people doing this at home:  'noirc=1' in your [whateveryoucallyourcoin].conf makes this much easier.

You'd think that people attempting to release a coin would at least have the FAINTEST idea how this stuff works.

+1 scam. Don't send them any money.

You now have 5 extra CHNCoin in your wallet. Hope that makes you feel slightly better.

Or if your employers would strongly frown on finding out what you're doing ;-)

Oh, of course. That's the 'other' answer. (The original one being 42, of course).

I'm sick of unreliable pools.
I'm sick of amateurishly set up systems.
I'm sick of lots of things.

So I'm going to do something about it.

Hello :-)