After having implemented this on my system, I opened it up to the rest of the world.
The system
is written in the low-level EVM code. This means that EVM code can encode any computation that can be conceivably carried out, including infinite loops. EVM code allows looping in two ways. First, there is a JUMP instruction that allows the program to jump back to a previous spot in the code, and a JUMPI instruction to do conditional jumping, allowing for statements like while x < 27: x = x * 2. Second, EVM code allows looping in the form of JUMPI, allowing for statements like while x < 27: x = x * 2. This allows looping through recursion, but it does lead to programs that become very space-inefficient as they go along. For example, implementing an alternative elliptic curve signature algorithm would likely require 256 repeated multiplication rounds all individually included in the code.
As an additional firewall, a new key pair should be used for each transaction to keep them from being linked to a common pool