Essentially correct. Kolmogorov complexity is the amount of information it takes to fully describe something. A million random bits have high complexity because

Essentially correct. Kolmogorov complexity is the amount of information it takes to fully describe something. A million random bits have high complexity because the shortest way to describe them is to literally list them all. The first million bits of pi have low complexity because they can be generated by an algorithm that takes much less than a million bits to describe. (The algorithm may take a long time to run, but Kolmogorov complexity doesn't care about that). From that perspective implementing a new login process for "just one client" is worse than changing it for everyone, because it increases the size of the program's description. The revised software must describe the existing login process, the new process, and the logic for deciding which clients use which process. Whereas changing it for everyone requires only describing the new process, and allows you to eliminate the description of the previous process.