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Final assembly

A project log for Hardware password manager

Small USB unit which simulates keyboard and generates, keeps and types up to eight passwords

voja-antonicVoja Antonic 05/29/2015 at 16:270 Comments

I received PCBs from my supplier and built the final version of the unit. Now I shall show it around to my friends, to hear their opinion.

I have upgraded the firmware a little. I added more password registers, so there are eight instead of four passwords. I also rearanged key functions a little, so the key which was named RNG will act as "Mode switch" key - it toggles between RED and BLUE led. Key NEW acts similarly to Shift or Ctrl key on the computer.

Here is the key function list:

Key ....................Red mode ..........................................Blue mode

A: .......................Type password A ............................Type password E
B: .......................Type password B ............................Type password F
C: .......................Type password C ............................Type password G
D: .......................Type password D ............................Type password H
NEW-A: ............Create and type password A ......Create and type password E
NEW-B: ............Create and type password B ......Create and type password F
NEW-C: ............Create and type password C ......Create and type password G
NEW-D: ............Create and type password D ......Create and type password H

Special functions:

RNG: Toggle between Red mode and Blue mode (this key will be renamed)
NEW-RNG in RED mode: Type password list
NEW-RNG in BLUE mode: Hex random stream

If the mode is RED, then the last command (NEW-RNG) is for backup password list creating. You open some text editor (Notepad or so), press NEW-RNG and get something like this (this was not typed on keyboard, byt generated directly from my unit - the only thing that I added are dots, as this editor does not like spaces in a row and does not support proportional fonts):

Password list

A: YwymSBLIf3GyzPyTuV0 .......... 34
B: 44XKZRtY9nJ7rouW2l ................ 2
C: BwULbiSIsS9pXyxl7b9 ............ 82
D: x0W2QMXWQuxOOVk ............ 19
E: yGa3poQ8SiuIEBGMZexc .......... 1
F: M5jVWc16Au8OmtYb ............... 36
G: c9bkTP9f8nbVzI6dkT13 ............. 1
H: Jeq6XTqRI1bR4Kg6 .................... 2

The last column shows how many times the password was invoked since it was created (this number should be at least 1, as the password is automayically invoked once immediately after its creation). You can use this counter state to check if someone used it without your knowledge.

Now you can print the password list and keep the paper at some safe place (do not keep it as a file on the computer - why did you build this unit then?)

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