Excel & Word Password Recovery

Originally Posted by MarkusO

This can't be really true.

There are lot of ways to optimize storage and search process.

Originally Posted by MarkusO

Storing 2^40 keys permuted to 2048 bits (RC4) would need 256 TB of hard disc space. While this could be possible in theory (with todays large datacenters), reading these 256 TB of data would take much longer than 3 minutes.

There is no need to store 2048 bits for each key. Actually just 40 bits of gamma will lead to very little amount of collisions.

For sorted data you could use binary search instead of linear one. For 2^40 values you need not more than 40 steps.

Also there are time-memory trade-off attack exists (see Rainbow tables for LM Hashes). But, to be honest, such approach has several disadvantages due to its statistical nature.

And, for sure, there are more ways to increase efficiency of keysearch exists