Technologies of MS Excel password recovery traditionally develop along three directions:
- Online services run decryption of protected files on company servers. Here, the user is required to upload their protected file to a decryption server. Since the files mostly carry sensitive information, many reasonably think it undesirable.
- The other way is to apply an attack method to try possible combinations of symbols (Brute-force attack and other type of attacks). For strong passwords it can take days without guaranteed success.
- Password removal is another alternative that can be effective but consumes time and resources on the user side (about ten days even on modern Pentium 4 computer).