According to Russian forensic security experts and 'password recovery' specialists ElcomSoft, the days of protecting documents and files with 40-bit encryption are now officially over.
It has now released a product which uses Thunder Tables technology to unlock password-protected documents that have been created using Microsoft Word. In fact, it guarantees that it can provide "near-instant recovery" of any such documents protected with 40-bit encryption. That compares with the days it would have taken using a straightforward brute-force approach.
Apparently the secret is the Thunder Tables technology, something that ElcomSoft claims is a result of "scientific research in cryptography" which ensures all 40-bit encryption keys are unlocked in seconds. These seem to be somewhat similar to Rainbow Tables, which come shipped on a DVD containing pre-computed hash tables. Rainbow Tables are well known in the security field, and can be sued to 'unlock' around 99 percent of encrypted documents in just a few minutes.
However, unlike Rainbow Tables the new Thunder Tables promise 100 percent 'password recovery' and in seconds rather than minutes.
They seem to work in a similar fashion though, pre-computing decryption information to speed up the password cracking process. With 40-bit encryption providing for a trillion possible keys, the Thunder Tables simply accounts for all of these possibilities as incredible as that may sound.