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by tromp 4543 days ago
Dagger appears to be inferior to the Cuckoo Cycle proof of work system I recently developed; see https://github.com/tromp/cuckoo

Cuckoo Cycle is a new proof of work system with the following features

1) proofs take the form of a length 42 cycle in the Cuckoo graph, so that verification only requires computing 42 hashes.

2) the graph size (number of nodes) can scale from 1x2^10 to 7x2^29 with 4 bytes needed per node, so memory use scales from 4KB to 14GB

3) running time is roughly linear in memory, at under 1s/4MB

4) there is no time-memory trade-off, and memory access patterns are the worst possible, making the algorithm constrained by memory latency

5) it has a natural notion of difficulty, namely the number of edges in the graph; above about 60% of size, a 42-cycle is almost guaranteed, but below 50% the probability starts to fall sharply

1 comments

What creates that upper limit of 7x2^29?
the naming convention that allows it to be named cuckoo729.

the program could be rewritten not to use bit 31 as a flag, and then you could use as many as 2^32-1 nodes, but that's not neatly expressible as MULT*2^SHIFT with few digits.