Appendix C: Previous Version Of Wired Master Encryption Key Generation; Previous Version Of Wired Master Encryption Key Generation Process - Blackberry ENTERPRISE SOLUTION SECURITY - ENTERPRISE SOLUTION - SECURITY TECHNICAL Overview

BlackBerry Enterprise Solution

Appendix C: Previous version of wired master encryption key generation

Each time a BlackBerry Enterprise Server or BlackBerry Desktop Software version earlier than 4.0 calls the
master encryption key generation function, the C language srand function is seeded with the current time to
generate a seed for the C language rand function. When the user responds to the BlackBerry Desktop Software
prompt by moving the mouse, the rand function is designed to generate random data based on the entropy that
the mouse movement gathers.

Previous version of wired master encryption key generation process

1. When the user moves the mouse, the BlackBerry Enterprise Server or BlackBerry Desktop Software
generates either 2 or 4 bits, depending on whether one or both of the x and y axes have changed. The
BlackBerry Enterprise Server or BlackBerry Desktop Software samples bits in this way until accumulating at
least 8 bits.
2. The rand function generates a random integer.
3. The BlackBerry Enterprise Server or BlackBerry Desktop Software examines the integer's least significant
bit. If the bit is a 1, the BlackBerry Enterprise Server or BlackBerry Desktop Software stores 1's complement
of the 8 accumulated bits; otherwise, the BlackBerry Enterprise Server or BlackBerry Desktop Software
stores the 8 accumulated bits unmodified. This process is designed to make sure that, even if a user
replicates a previous user's mouse movements (which is virtually impossible), the resulting value is still
unique.
4. The algorithm loops until the BlackBerry Enterprise Server or BlackBerry Desktop Software has sampled 256
random bits from the user's mouse movements.
5. The BlackBerry Enterprise Server or BlackBerry Desktop Software uses the SHA-1 function to hash the 256
bits.
6. The BlackBerry Enterprise Server or BlackBerry Desktop Software generates the master encryption key
using the first 128 bits of the resulting hash.
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