I'll be speaking at BlackHat USA 2008 in Vegas this August. My abstract follows:
The Texas Instruments MSP430 low-power microcontroller is used in many medical, industrial, and consumer devices. It may be programmed by JTAG, Spy-Bi-Wire, or a serial BootStrap Loader (BSL) which resides in masked ROM.
By design, JTAG may be disabled by blowing a fuse. The BSL may be disabled by setting a value in flash memory. When enabled, the BSL is protected by a 32-byte password. If these access controls are circumvented, a device's firmware may be extracted or replaced.
After a thorough introduction, this talk will discuss in excruciating detail the results of an effort to reverse engineer the BSL code. Once the BSL's function has been covered, a timing attack will be discussed which might be used to guess the password without brute force under certain conditions.
<travis at utk.edu>