rEn1YW3hSH4pA7cXZ184fW66KYB9pt38YG

anti-scam is right, you'd have to be careful with the math so you didn't wind up with blockchains accidentally diverging all over the place. Let's give ourselves a few definitions so we're on the same page.

The credibility C of a blockchain is a function of the blocks in that chain. The work W is a measure of how much work went into a given block. The age A of a block is how long ago this node first saw that block. Right now, this looks like:

    C = sum of W(b)

But there's no reason it couldn't look like this:

    C = sum of W(b) * F(A(b))

where F(t) is some function of the a block's age.

The hard part is how you pick for F(t). Discuss!

Hi everyone!

I've been a lurker on these forums for a while, but now I actually have a genuine question so I figured I'd start getting those newbie posts out of the way.  I'm almost certain this has been asked before so it's perfect fodder for the newbie forum, but I couldn't find it anywhere.  So here goes.

The Stanford paper pointed out two interesting things.

First, as long as Moore's law holds, the cost of attacking the entire blockchain is proportional to the cost of attacking the last hour.  Or day.  Or whatever.  Granted, that's a large proportion, but that seems to be exactly the fear that led to Bitcoin's current checkpointing solution.  But centralized checkpoints suck.

Second, you can achieve a sort of decentralized checkpointing by making old nodes skeptical of blocks that would invalidate blocks they themselves witnessed a long time ago.  So revisionist histories would require more and more proof of work the more (and older) blocks they invalidated.

This seems like an awesome idea, but since the paper was published in 2012 and Bitcoin hasn't done this yet, I'm assuming there's something wrong with it.  What am I missing?