The essence of this proposal involves retaining miners on the SHA256 algorithm but introducing an additional requirement for them to hash their block headers twice to meet a secondary difficulty target. This mechanism is designed to activate at the maximum target difficulty, where miners are expected to publish blocks only when two conditions are met: first, the SHA256 hash of the block header equals 1, and second, the double SHA256 hash of the same header is less than or equal to a secondary target.

This secondary target is dynamic; it adjusts upward or downward if the primary target is set at 1, which currently represents the highest level of difficulty target in the mining process. The verification of blocks by nodes incorporates checking that the initial SHA256 hash of the block header equals 1, and subsequently, ensuring the double SHA256 hash is below the secondary target. This approach aims to maintain the integrity and security of the blockchain while enabling a more flexible adjustment of mining difficulty levels within the constraints of the existing SHA256 algorithm.