SHRIMPS: 2.5 KB post-quantum signatures across multiple stateful devices

A follow-on Delving Bitcoin proposal that targets a practical wallet problem the smaller SHRINCS scheme makes awkward: using the same key safely across several devices. SHRIMPS combines two SPHINCS+ instances under one public key — a compact instance sized to a bounded number of device initializations, plus a higher-capacity fallback.

The result is larger than SHRINCS, around 2.5 kB per signature, but still roughly a third the size of the standardized SLH-DSA, while letting the same seed be loaded onto multiple independent signers. It is presented as one point on the size-versus-flexibility trade-off, not as a settled recommendation.