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1  Alternate cryptocurrencies / Altcoin Discussion / Re: Do not mine these new coins!! on: May 22, 2013, 07:44:23 PM
Worldcoin has a 15 second block target, so it gets a huge number of orphans and blockchain forks. I just wouldn't recommend mining any coin with less than a 60 second block target. But if the coin still makes profits even though you are getting a large number of orphans then why not.

And yes calculators will not factor in orphans. The calculators are designed for litecoin where orphans are extremely rare. Worldcoin by design (flaw) will have orphans like mad.

Also do note: you may not get any orphans showing up in your mining software, but the pool itself will be getting lots of orphans. So even if your software says the orphan rate is like 2%, the pool itself may be getting 15-20% orphans.
2  Alternate cryptocurrencies / Altcoin Discussion / Re: Request for SHA-3 coin on: May 22, 2013, 07:38:24 PM
Yes, I was going to say, Yacoin uses SHA-3 with chacha in its scrypt implementation instead of the sha256 with salsa that litecoin uses.

So if you're looking for a SHA-3 coin, there you have it. It's already on an exchange too. Though last I checked it wasn't worth mining but that may have changed.
3  Alternate cryptocurrencies / Altcoin Discussion / [WTS] 2700 worldcoins for 3 LTC/100 WDC [SOLD] on: May 20, 2013, 04:18:48 AM
 - SOLD - Thanks for the interest!

I have no reputation so let's use this escrow service: http://exchange.dudeami.com/ -- it's new but people have tested it and say it works.

Selling in lots of 100, 2700 worldcoins total. Looking for 3 LTC/100 WDC or 81 LTC total.

Please private message me. Offer expires in 1 hour from now. Thanks.
4  Alternate cryptocurrencies / Altcoin Discussion / Re: [Update] Root (4-Week Altcoin Announcement) on: May 19, 2013, 06:22:50 PM
At first glance this looks good.

One problem is that the word Root is a swear word in at least one english speaking country. I as far as I know anyway. Maybe it's route that's the swear. An Australian will be able to correct me if I'm wrong. But from what I've been told it's worse than f*ck.

Otherwise I like the higher start difficulty and the fewer rewards for early adopters. That should stave off the normal pump and dump crew and might allow the coin to survive.

I would like to see something innovative though. Like maybe a way to have super fast, safe transactions without having any blockchain bloat. I can think of at least two ways that might just work for how to do that. One is having a mini-chain with a few second confirm time that gets reset every block of the main chain. Another is to have some consensus system like ripple. Both would take quite a bit of work to implement, but if they work it would make your coin much better than any other.
5  Alternate cryptocurrencies / Altcoin Discussion / Re: Altcoins and Checkpoins? on: May 18, 2013, 12:45:28 AM
put an equals sign between -connect and the IP. so -connect=1.1.1.1 -- also make sure the IP is actually the IP of the machine in question.
6  Alternate cryptocurrencies / Altcoin Discussion / Re: [PSA] Attention: Security vulnerability in new alt coins! on: May 18, 2013, 12:07:25 AM
Yes I figured out what you need to do to set the difficulty of the genesis block. It's in the nBits field of the genesis block. If you set the nBits field to bnProofOfWorkLimit.GetCompact() that should ensure that the genesis block and the blocks after it have the difficulty set by bnProofOfWorkLimit. I think anyway. I am not 100% sure.
7  Alternate cryptocurrencies / Altcoin Discussion / Re: Altcoins and Checkpoins? on: May 17, 2013, 11:11:00 PM
I also found where the magic number is in the code. main.cpp pchMessageStart defined around line 2439 or so just before the definition of ProcessMessage. You should change that to be different than any existing coins or bad things.

Basically this number will allow your coin to ignore protocol messages from other coins thus ensuring your coin's chain won't become infected with transactions and/or blocks from other chains by accident.

You should choose values that are extremely unlikely to occur in normal valid messages. It suggests values above 0x80 since values below 0x80 are valid ascii.

Choosing random values between 0x80 and 0xfe would probably be okay. It's very unlikely two coins will choose the same random numbers. I suggest the first number be between 0xf0 and 0xfe but it doesn't have to be.

The testnet magic number should be different from the normal net. The testnet magic number is set in LoadBlockIndex at the top I think. Also main.cpp.
8  Alternate cryptocurrencies / Altcoin Discussion / Re: Altcoins and Checkpoins? on: May 17, 2013, 10:49:10 PM
Well I am a professional software developer. I do this for a living. I wouldn't be worth much if I couldn't take something as well written as the bitcoin client and figure out how to modify it.

The main protocol port is in protocol.h in a function called GetDefaultPort. You should also change init.cpp so the help message matches the port you choose in the GetDefaultPort. That's for the protocol port.

The default RPC port is found twice in bitcoinrpc.cpp in calls to GetArg("-rpcport", ####) where #### is the default port of whatever coin you're using as the original source. Like the protocol port, it's mentioned in the help strings in init.cpp so should be changed there too.
9  Alternate cryptocurrencies / Altcoin Discussion / Re: Altcoins and Checkpoins? on: May 17, 2013, 06:26:55 PM
Does it matter what port # I change it to? Does it have to be specific or can I just change like the last number in the sequence and it will work?

Do enough research to be reasonably sure you're not using a port number from any other coin. If you're not sure pick a random one between 10000 and 20000 -- only two coins I'm aware of have used numbers in that range (worldcoin and one other coin I forget the name of), so if you pick it randomly you probably won't pick the same one. Testnet would be that port plus 10000. RPC port is that port plus one.
10  Alternate cryptocurrencies / Altcoin Discussion / Re: Altcoins and Checkpoins? on: May 17, 2013, 03:48:23 AM
Sorry I'm sure you got something better to do with your time then help a noob like me but I just have one more question (more like a few):

Should I change the ports? does it matter what I change them to?

Yes change the ports for the same reason. Otherwise other coins can connect to your client and attempt to send blocks and transactions to it. That's bad. IIRC there's also some magic numbers you need to change so if somehow another coin does connect to one of your clients, any blocks or transactions sent from it are invalid and will be dropped. And vice versa of course.

I don't know where these magic numbers are in the code. I haven't studied the code very closely because right now I don't intend to make an altcoin.
11  Alternate cryptocurrencies / Altcoin Discussion / Re: Altcoins and Checkpoins? on: May 17, 2013, 02:31:50 AM
how would I go about setting up an irc channel? using freenode or would I have to set up my own server too?

Keep the server the same. Just change the name in the string. If the channel doesn't exist on the server in question it will be created. Done. When all the clients leave the channel the IRC server will destroy the channel.

Just keep the IRC server the same. FreeNode would probably not appreciate bitcoin traffic. But I presume someone at some point asked the default IRC server admins if they could use it for bitcoin traffic.
12  Alternate cryptocurrencies / Altcoin Discussion / Re: Altcoins and Checkpoins? on: May 17, 2013, 02:21:56 AM
The irc is how it gets IP addresses for nodes, and it does this by looking at join messages in the IRC channel it's in. If you don't create a new channel then you will get peers from whatever other coin is in that channel. That's bad. You should have your own channel for your coin. Otherwise it will take forever for any new users of your coin to find peers, because all of the IP addresses it will try from IRC are not using your coin but someone else's.
13  Alternate cryptocurrencies / Altcoin Discussion / Re: [PSA] Attention: Security vulnerability in new alt coins! on: May 17, 2013, 02:17:04 AM
Please don't show anyone where to make the change - if someone can't figure that out, then they have no business releasing code that they have no real clue how it works

These people are going to create copy-pasta clones anyway. If we don't educate them they will be forever without this knowledge. So I encourage you to explain how to make this modification. I am sick and tired of all these clones starting at retardedly low difficulty.

The tool u mention already exists.. it's called cgminer.. or cpuminer...

you simply start a few daemons with the -connect option. That ensures it only connects to one node (which is also yours).. then you instruct your rigs to mine on your node.. as soon as you have a height > current blockheight you disconnect one daemon and restart it without the -connect option.. Voilá..

And yacoin, yes I think this has been done..

Hmmmm... If it's that easy then it's absolutely silly that these copy-pasta clones start at such a ridiculously low difficulty.

Again, if you have knowledge of how to set the initial difficulty higher please share it. The recent flood of clones is obviously being done by amateurs that probably won't figure this out, and yet will release their coins anyway. So do everyone a favour and educate them. Maybe they will listen.
14  Alternate cryptocurrencies / Altcoin Discussion / Re: [PSA] Attention: Security vulnerability in new alt coins! on: May 16, 2013, 05:15:46 PM
Copy-pasta was intentional :-) I stole it from someone on IRC I think but I thought it was very fitting.
15  Alternate cryptocurrencies / Altcoin Discussion / Re: [PSA] Attention: Security vulnerability in new alt coins! on: May 16, 2013, 07:00:41 AM
Yeah I am mining worldcoin because I am bored. I do not expect it to hit an exchange, nor do I expect to be able to sell it for anything more than pennies if it does.

It would be nice if a coin came along that was a serious distraction from litecoin so litecoin's difficulty would go down though. And these copy-pasta clones are not going to do it.
16  Alternate cryptocurrencies / Altcoin Discussion / Re: [PSA] Attention: Security vulnerability in new alt coins! on: May 16, 2013, 06:41:24 AM
Worldcoin just hit difficulty 0.25 now, and it's getting coins every 1-5 seconds at current hashrate. That's pretty good, considering the minimum scan time in cgminer is 1 second, that means if you have cgminer getwork every second you have a good chance of having almost no stales. You also have very low load on the network. Still a lot of orphans but a lot less than 99.9% orphan rate I was getting for the first few hours.

I was seeing more than 5 blocks per second on worldcoin when I checked. I don't know what the peak was but that's pretty crazy.

EDIT: 5 blocks per second at first I mean.
17  Alternate cryptocurrencies / Altcoin Discussion / Re: [PSA] Attention: Security vulnerability in new alt coins! on: May 16, 2013, 06:25:22 AM
What are you talking about...? At difficulty 0.25 with 350 KH/s you should find a block roughly every hour, that is hardly scraps. Coins shouldn't be made with the intention of everyone getting thousands of coins in the first few days so they can hoard them until the coin reaches an exchange and then dump their thousands of coins on the market decreasing the value of the coin instantaneously. Any coin designed to be intentionally pumped and dumped shouldn't bother being released.

I agree. For a GPU mined coin 0.25 is a pretty fair starting difficulty. There will be MUCH fewer orphans, and people will still get a large number of coins in the first few days. It's just the coins will be spread out to more miners that's all.
18  Alternate cryptocurrencies / Altcoin Discussion / Re: [PSA] Attention: Security vulnerability in new alt coins! on: May 16, 2013, 06:16:15 AM
While this is probably true, if they started at a difficulty of 1, or .25, and the coin became popular, very quickly, it would be impossible to get coins, and if it was traded, the coin would be unprofitable to mine.  So that means basically anyone without 10 - 30 MH's rigs (for litecoin variants) would get scraps, where as currently with some of the new coins, anyone who sees a release quick enough,m even with minimal hashing power, can scoop up a few thousand coins and possible a nice profit if its traded.  I say something like .025 would be a better start than .25 or 1.

What was Bitcoin's original starting difficulty, anyone know?

Okay well if you really want to premine the shit out of it, the minimum *safe* starting difficulty can be calculated using the following equation:

difficutly = plausible_attacker_hashrate * time_per_block / 2^32

So using 2 blocks per second and an attacker with 50 MHash/s that would make the minimum sane starting difficulty 0.0058207. Anything lower than that and an attacker with 50 MHash/s or less can hijack the network easily. But 0.005 is not a very fair starting difficulty in my opinion, as it will still be an orphan-fest for everyone mining.
19  Alternate cryptocurrencies / Altcoin Discussion / Re: [PSA] Attention: Security vulnerability in new alt coins! on: May 16, 2013, 05:57:52 AM
As much as I agree that starting a coin with base difficulty is just fucking retarded, I seriously doubt the majority are going to listen. This exact issue is addressed and complained about hundreds of times per week and it doesn't seem to be changing anything.

But still, I totally agree and +1 OP

Well I figure maybe some math and a convincing blurb on why it's against their best interest to do this silliness might convince some people. Maybe. We can only hope.

Anyway c4n10 I can't wait for your coin to come out with its 0.25 start difficulty. Hopefully some people start using your idea. Maybe it would help if you write a few words explaining how to properly set the initial difficulty to 0.25?
20  Alternate cryptocurrencies / Altcoin Discussion / [PSA] Attention: Security vulnerability in new alt coins! on: May 16, 2013, 04:21:27 AM
Please do not start at zero difficulty (0.00024414 to be precise, which is the default start difficulty of litecoin). I know you're hoping to get rich quick but here's why you should not do this: 51% attack.

All someone has to do is build a tool that will mine valid blocks using GPUs as quickly as possible without asking the network if the blocks are valid or not (except the first one). Then you periodically broadcast your attack chain to the network without caring at all about the longest chain seen by your client from the network. As long as the chain is valid this will work.

With the difficulty at the default of 0.00024414, all you need is 0.00024414 * 2^23 * 10 = 10.5 MHash/s to be able to mine 10 blocks per second (the equation is difficulty * 2^32 * blocks_per_second = hashrate_required). I have noticed usually the network is only able to go 2-5 blocks per second because of network latency, and nearly everyone is getting 95%+ orphans thus wasting their hashing power. So at 10 blocks per second an attacker would have absolutely no problem mining faster than a network that's having a laggy orphan-fest. And 10.5 MHash/s is cheap... quite a lot of people have that or more. You might even be able to pull off this attack with just 5 MHash/s as long as you can build your chain faster than the legit network can.

If your new or upcoming coin uses scrypt the above tool will be able to attack your coin! I don't even think there's any need for the tool to be modified for new coins in order to work, it just needs to grab your genesis block and then go nuts producing blocks as fast as it can, periodically broadcasting its chain to ensure if you use checkpoints there's a high chance you'll checkpoint the chain it's produced. It might need some tweaking knobs for commonly changed parameters like the difficulty retarget period, number of coins per block, etc. It's also quite possible this tool could be made by using a simple proxy wrapper around the *coind server to censor data coming in to ensure it's not aware of other chains but the attacker's chain. This ensures the attacker will be able to jump on your new coin an hijack the chain as soon as you launch.

If anyone can prove that the above tool cannot be created, I am all ears. Please quote source code or something as proof. But as far as I know I am correct and it's possible to perform this attack provided the difficulty is low enough.

TL;DR New altcoin authors, please stop using the default litecoin starting difficulty. Please use a sane value such as 0.25 or 1.0 as the starting difficulty. Otherwise a 51% attack can easily steal all your and your early adopter's coins! Checkpoints will not foil this attack!
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