Kaspa Explained

Chapter 05 · Try to break it

Try to cheat.

The one attack that matters: rewrite history to spend coins twice. Mine in secret, release, try to jump the queue.

Why the hidden blocks turn red

While you hid, the honest network kept making blocks your branch never saw. That gap is your blocks’ anticone. A block stays blue only if at most k blue blocks sit in its anticone. Honest blocks, published at once, have small anticones. Yours has a huge one, so it’s colored red and ordered after the honest ones. Red blocks still count; they just can’t jump the queue.

How certainty grows

Slide the burial deeper and the catch-up chance falls off a cliff. Slide the attacker's share up, and even a deep payment wobbles.

The classic catch-up calculation from the Bitcoin paper, computed in your browser. Kaspa counts burial in blue score rather than blocks; the shape is the same, and the fall is the point.

The one sentenceHide blocks, race them, split the network: the order still lands where the rule says it lands.

The exact version

The same chapter with the workings shown: the derivations, the edge cases, and the numbers behind the plain version.

Play it for coffee: the same attack, as odds

Now play it for coffee.

You buy a coffee, then mine in secret to undo the payment. The shop hands it over after a set wait. If your hidden blocks ever outnumber the honest ones after that, you release them and keep both the coffee and your coins.

Your share of all mining
The shop waits
Your odds

The odds are the Bitcoin white paper’s race math (section 11, bitcoin.pdf; Rosenfeld 2014) at Kaspa’s 10 blocks a second, worked out exactly for a shop that waits a set time. A teaching model: it counts blocks and ignores network delay and the DAG’s width. The honest catch: near half of all mining, even a 10 s wait leaves a cheater real odds. That holds for every proof-of-work coin; it is why a shop’s wait should match the cheater it fears.

Sources and the raw numbers

Read more

The slider stops at 45%: past half of all mining, any proof-of-work coin can be rewritten, Bitcoin included. A teaching model with = 3; the real network sets k from its block rate.