Combination Lock Opener. Bill Samore Brian Elies Mike Arthur. Intro, Features, Cracking the MasterLock ®, Stepper Motor & Driver- Bill Photo Sensors, Flywheel, Solenoid, H-Bridge- Brian PIC, Keypad, 7-Segment Display, Gate Detection & Opening the Lock- Mike
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Intro, Features, Cracking the MasterLock®, Stepper Motor & Driver- Bill
Photo Sensors, Flywheel, Solenoid, H-Bridge- Brian
PIC, Keypad, 7-Segment Display, Gate Detection & Opening the Lock- Mike
Time to Open Lock, Ethics- Bill
Testing and Conclusion- Brian
Many people forget the combination to their lock and then need to buy a new one.
If it took a person 15 seconds to enter a combination it would take 11 days 2 hours and 40 minutes to try all 64,000 possible combination.
Our combination lock opening device narrows the possible combinations down to 80, and then tries each one of those to discover the correct combination.
There will be 12 gates.
5 of the gates will be whole numbers and 7 will be half numbers.
The last digit of one of the whole numbers will be different than the rest: This is the 3rd number of the combination!Cracking the MasterLock ®
Gates from one of our Locks:
3rd number of the combo!
Take the 3rd number of your combination and divide it by 4.
Take the remainder and record it- this is the first possibility for the first number in the combination. The other possible first numbers of the combination are found by adding 4 to this number until the highest possible number (39) is reached.Cracking the MasterLock ®
Our example continued:
3rd number of combination = 20
20 % 4 = 0
Possible 1st numbers of the combination:
Take the remainder from earlier. If it was a 0 or 1 add two to it. If it was a 3 or 4 subtract two from it.
This is the first possibility for the second number in the combination. The other possible second numbers to the combination are found by adding 4 to this number until the highest possible number (39) is reached.Cracking the MasterLock ®
Our example continued:
Remainder from before = 0
0 + 2 = 2
Possible 2nd numbers of the combination:
We now have 10X10 = 100 possible combinations. to it. If it was a 3 or 4 subtract two from it.
However all combinations must be either low-high-low or high-low-high this eliminates 20 possible combinations
There are 100-20= 80 possible combinationsCracking the MasterLock ®
Our example continued:
is low-high-low so it is possible
Is high low high so it is possible
is neither low-high-low nor high-low-high so it is notpossible and we do not need to try it
Stepper Motor to it. If it was a 3 or 4 subtract two from it.
Whole Number divisions
20 black and 20 white
Half Number divisions
40 black and 40 white
The black mark is aligned with zero on the lock
Opens the lock
Assists with Gate detection
Connected to the latch of the lock with a zip tie
The lock is held in place via an indentation in the aluminum cross bar
PIC is programmed to decide from the three trials what the most likely gates are -based on the results of the trials and known data of where gates often are
From these gates, the PIC identifies the one that is different from the other gates as the last number
Displays last number after calculatedLast number Calculations
Device tries all 80 possible combinations with that last number – displays combination as it is trying it
If this device were to be marketed, these and all other break points would removedAttempts to open lock
Sample gates can be hard coded and the device is able to engage in a mode where it will determine the most likely gates from the hard coded data
Useful to confirm that correct gate locations are being determinedTesting – Finding Most Likely Gates
1.) Find all of the internal gates. This takes about 6 min
2.) Try all 80 of the possible combinations. It takes an average of 17 seconds to try 1 combination or about 23 min to try all 80. Therefore the expected time for step 2 is 11.5 minutes.
Total Expected Time = 6 + 11.5 = 17.5 min
Sensor readings engage in a mode where it will determine the most likely gates from the hard coded data
Mass Combination entry
Our device should only be used to find the combination to one’s own lock. Not to break into someone else’s!
It would be very difficult to fit a lock into our device if it was attached to anything such as a lockerEthical Considerations
Saves time and money
Can find combination to any Master Lock®
Time consuming to change lock
Gate detection unreliable
New software for other brands of locks.
Reduced time to crack lock
Stores that sell locks
Gym/High School Locker rooms
% Error for gate detection one’s own lock. Not to break into someone else’s!
Mode: M-82 manufactured: Pontiac Coil Inc. one’s own lock. Not to break into someone else’s!
Exerts a force of about 75 ounces at a distance of .25 inches.
a latching solenoidSolenoid Specification