Quote from: tromp on Today at 10:48:54 AM

Quote from: markm on Today at 09:55:30 AM

GRouPcoin is merged-mined but I am not sure if anyone or manyones do that anymore.

What is the cumulative work achieved by GRP up till today? How long would it take all bitcoin miners to achieve that amount of cumulative work?

I am not sure, I'd have to look at code again to try to find where cumulative work is calculated and add a printout of it unless one of the rpc commands or command-line switches outputs that information.

One of the best objections to merged mining is precisely the fact that unless the majority of bitcoin-mining hashpower merges all the mergeable coins, some of them are going to be vulnerable to the possibility that all those not merging it for good decide to merge it for evil as it were.

Maybe by using non-SHA256d ASICs enough to combat a majority of the world's GPUs and FPGAs, and continuing to buy up such ASICs faster than potential attackers can or do, you can hope to achieve the security bitcoin enjoys?

However by trading on an IOU-trading platform such as Ripple or Stellar or nowadays a lot of alternative IOU-trading (aka token-trading) platforms you can gain a layer of protection against attempts to interfere with the blockchain by releasing a new node version with added checkpoints before tokenising coins minted before the new checkpoint, and wait any arbitrary number of blocks before actually issuing the tokens representing the newly-bailed-in specie.

Also of course any alien blockchain appearing out of no-where attempting to cause a re-org going back more blocks than typical nodes can handle is going to choke up nodes, coming to the attention of those who run the blockchain, all of whom probably add new checkpoints of their own in their own nodes any time they feel nervous about the possibility of such attacks.

For example I just heard a few hours ago from a chap who updates coin code over the years that apparently the gang of scammers running around pretending to "revive" ancient coins has as long ago as last August or earlier been promulgating a scam "FairBriX" coin. The aforementioned coder actually wrote an updated FairBriX from the latest LiTeCoin code, adding a block at which the difficulty calculation would change, because those scammers had apparently fallen victim to an attacker having even more scrypt power at hand than they did; the attacker did to their new scam FairBriX what they or maybe the same hacker had already done to the original FairBriX: driven it to high difficulty and flow by night, leaving it requiring gosh knows how long for the remaining miners to get the difficulty down again.

Examining the original chain we found actually it was still many blocks away from the activation block of his new code, but an explorer supposedly exploring the scammer's latest attempt to hijack the chain showed it was long long past the activation block. He mentioned checking somewhere else, maybe an exchange even, and finding it was not on the original chain nor on the scammer's latest chain, so maybe had been left in the lurch when the scammers abandoned their first attempt and moved on to who knows how many more before arriving at the version shown in the explorer. I am guessing not many more simply because they seem to be serial scammers going from coin to coin attempting such things so likely would have moved on to another victim-chain rather than wasting too much time on one that just didn't seem to be working out for them.

A few months or so ago some chap did PM me about obtaining some FBX from me, bought some of my FBX IOUs on Stellar and had me redeem them for him, and has not been back to complain, so I imagine whatver exchange he was planning to trade them on was on the original chain at that time, but weeks later I got curious and clocked the link he had given me of the exchange he said he was going to use and it had by then already seemingly "flown by night" as it were.

The moral of the story is that high hashpower attackers can be a problem but FairBriX is showing as we type that all they really accomplished so far is to push its blockchain to high difficulty then fly by night leaving it hard to pump out blocks with remaining miners and thus to take a long time to ever get to the block at which a fix to the difficulty calculation comes into effect or the blocks at which the difficult will adjust downward in accordance with its current difficulty-adjustment algorithm.

Annoying, but no original-chain coins lost unless that chap who bought some from me handed them over to the scammers or the flew by night exchange.

-MarkM-