Can a Password be Derived from a AES key? This thought randomly popped into my head and I have not been able to find a clear, defined answer for it. Given an AES key, lets say an AES-256 key which is derived from a user password, is there any way to analyze the key and reverse engineer the password used to generate the key?

I understand if the key has been revealed and is known to an attacker they already have what they need, but this is a theoretical. Alternatively, a hacker may leverage a weakly protected system, stealing the key for a particular user from that system, reverse engineer the password then hope the user used the same password on a more secure system that the hackers primary goal is to access that.

I apologize if this is an obvious question, I am a software developer trying to break into the security field and attempting to develop my understanding of cryptographic principles.

Thanks!
Given an AES key, lets say an AES-256 key which is derived from a user password, is there any way to analyze the key and reverse engineer the password used to generate the key?


This is really the same problem as password cracking, where the simple strategy of trying statistically likely passwords at very high speed with specialized, massively parallel hardware (e.g., GPUs) has proven to be very fruitful.  This doesn't involve any sort of cryptanalytic attack to reverse the key derivation function, rather just relying on (a) the predictability of real-world passwords and (b) the fitness of GPUs for this sort of task.

If you're not familiar with this topic, this article and the enclosed video are a good primer.