Yes, I'll go ahead and send you a link to the source and assets later tonight. I can strip out the portions that are untested. But it should still work for your needs. Here's a quick rundown of the two types of protectors:
Shared Protector
Restricts building and mining within an 11m cubic area except by the owner or designated members. Digging and mining by members can be further restricted according to the bitmap mask of the area (see below). Shared Protectors can be useful for creating apartments and shared tree farms.
Public Protector
Restricts building and mining within an 11m cubic area according to the bitmap mask of the area (see below). Public Protectors can be useful for creating public tree farms and sandbox playgrounds.
The bitmap mask of shared protectors can be manually engaged or disengaged by right-clicking the protector and clicking "Lock Area" or "Unlock Area" respectively. Locking the area stores a "snapshot" of all non-air and non-liquid nodes as a bitmap into the metadata of the protector (compressed for space efficiency) . For public protectors, the bitmap mask is automatically engaged at all times.
I also resolved the long-range dig exploit, whereby hackers could dig nodes adjacent to unloaded mapblocks to evade protection. The server operator, of course, can bypass this restriction.
Tip: If there are overlapping protected areas owned by the same player, then the most restrictive bitmap mask is used to determine whether any given node is protected from mining or building.
Tip: When engaging a bitmap mask, only air and liquid nodes are unmasked and all other nodes are masked. To protect an open area (like a hallway), it should be filled temporarily beforehand.