Two lists one with keys and with values. The key list can be delta encoded and then compressed with the assumption that most of the deltas are small (even with

Two lists one with keys and with values. The key list can be delta encoded and then compressed with the assumption that most of the deltas are small (even with adversarial keys this property must hold, as if there are too many big deltas then it would overflow the key type but we know all the keys are valid).