Security Co-Processor (PadLock)
VIA C7-M includes a unique feature that is a security co-processor, called PadLock. Mobile computers face a huge security problem, since if your mobile computer is stolen or lost, anyone can gave access to your data. PadLock is basically an encryption engine, a hash engine and also a random number generator (RNG).
The encryption engine supports all AES modes and according to VIA, C7-M is capable of performing encryption at a rate of up to 25 GB/s.
PadLock co-processor also has a hash engine, which is used to check if a data was altered. According to VIA, C7-M is capable of performing hashing at a rate of up to 20 GB/s and it supports SHA-1 and SHA-256 methods.
The security co-processor also has a Montgomery Multiplier engine, accelerating calculations required by RSA encryption algorithms.
And finally, PadLock incorporates two random number generators, with a performance up to 12 MB/s. Random number generators are key to encryption because they generate true random numbers. When the computer doesn’t have this feature (almost all computers don’t have), a random number is generated using the real time clock. So a hacker, knowing more or less the date and time you created a random key, can break it more easily using proper tools.
In Figure 9 you have a security features comparison between VIA C7-M and other mobile processors.