I'm confused why the vendor would use AES-256. There are 5 wheels, each with 27 possible values, so: 27^5=14,348,907 total possible combinations. AES-128 has 340,282,366,920,938,000,000,000,000,000,000,000,000 (2^128) possible values and AES-256 has 2^256 possible values. So the only thing the stronger crypto provides is a 20% increase in CPU time, a decrease in read/write performance, and an increase in power usage.

I'm confused why the vendor would use AES-256. There are 5 wheels, each with 27 possible values, so: 27^5=14,348,907 total possible combinations. AES-128 has 340,282,366,920,938,000,000,000,000,000,000,000,000 (2^128) possible values and AES-256 has 2^256 possible values. So the only thing the stronger crypto provides is a 20% increase in CPU time, a decrease in read/write performance, and an increase in power usage.