Miners employing parallel validation do not fall victim to extended time validating blocks containing aberrant large quadratic hashing time transactions. Instead, they orphan such blocks. By continuing to mine and validate on other threads while the validation of the aberrant quadratic hashing time block runs on one other thread. Miners who continue to make blocks with such transactions will eventually bankrupt themselves. All without doing any damage to the network. Problem solved.
What implementation includes parallel validation? Oh yeah... BU does.
Given the massive amounts of ram required by ultra large transactions that are heavy in sigops that would be prone the quadratic scaling laws, validating yet another block in parallel is an excellent way of using even more ram. High ram servers with 256GB may be able to cope temporarily with it but normal machines and even normal servers will likely run out of memory and kill bitcoind.
Which implementation has had out of memory issues already? Oh yeah... BU did.
You don't think the significant mining pools can afford one large server each?
this is why you dont let TX's get MORE bloated when block sizes increase.
best option is to keep tx's at or below 4k sigops. the quadratics are copable and capable on normal machines
EG things like
< 4ktxsigops
< 100k txmaxbytes
that way for instance..
spam attack
1mb block requires 5tx sigop spam or requires 10tx bloat data spam
2mb block requires 10tx sigop spam or requires 20tx bloat data spam
4mb block requires 10tx sigop spam or requires 40tx bloat data spam
some people think going up is ok (facepalm) (where sigops per tx and bytes per tx goes up with blocksize)
1mb block requires 5tx sigop spam or requires 10tx bloat data spam
2mb block requires 5tx sigop spam or requires 10tx bloat data spam
4mb block requires 5tx sigop spam or requires 10tx bloat data spam
some people think going down is bad (facepalm) , yet if txsigops went to say 1k and txmaxbyte =50k
1mb block requires 20tx sigop spam or requires 20tx bloat data spam
2mb block requires 40tx sigop spam or requires 40tx bloat data spam
4mb block requires 80tx sigop spam or requires 80tx bloat data spam
where by at 4mb block for instance even using max tx sigops the time to process is seconds not minutes