Since a few weeks, I am the owner of a Nokia N95 8GB.
I managed to configure it to match my preferences, so I decided to give data security a bit more attention. Previously, I switched on the SIM-lock and the device lock functions. The device lock is a code that blocks the device after it has not been used for a given time (or after the user locks it manually).
The device lock code was a bit too simple, so I decided to change it. I made up a code, entered the old code, then the new code, then repeated the new code and the process was complete.
The next time I tried to unlock the device, it reported failure. I was very sure that I had used the correct code. Also the old (simple) code did not work anymore.
After some time, I discovered what went wrong:
- The new code I made up was a series of 6 digits
- The device lock code is a 5-digit code
- Apparently, the phone accepted my 6-digit code (initial entry and check) but did not use all 6 characters
Question remaining is: what did the phone remember from the 6-digit code I entered? Probably 5 digits (as the device lock code is a 5-digit code), but which 5?
After some attempts (after a few mismatches, you'll have to wait 5 minutes between every single attempt), I found out that: "in case you correctly enter a 6-digit code as your new device lock code, the phone uses the first 5 digits you entered". Makes sense, but I tell you I had a hard time before I found this out.
Probably, this "undocumented feature" is related to the way the codes are stored (hashed, hopefully). However, I wish to express my sincere thanks to Nokia for this user interface flaw that cost me a few hours of work. If ony 5 digits are allowed as a code, why allow more? Why not inform the user? Why accept the 6-digit code entered by the user?
And, I am sorry to say that it is not the only issue. The dear N95 requires a hard reset every day. And with a hard reset, I mean that the battery has to be removed and placed back.
[update:] Due to a constant stream of annoying comments asking how the phone's security can be broken, I have decided to switch off comments for this posting. Once and for all: when you don't know the security code anymore, you should go to you reseller or a Nokia representative and prove that you're the rightful owner. Maybe they'll be able to help you. I can and will not help you with this. [end of update]