Secure computation environments are protected from bogus or rogue load
modules, executables and other data elements through use of digital
signatures, seals and certificates issued by a verifying authority. A
verifying authority--which may be a trusted independent third
party--tests the load modules or other executables to verify that their
corresponding specifications are accurate and complete, and then
digitally signs the load module or other executable based on tamper
resistance work factor classification. Secure computation environments
with different tamper resistance work factors use different verification
digital signature authentication techniques (e.g., different signature
algorithms and/or signature verification keys)--allowing one tamper
resistance work factor environment to protect itself against load modules
from another, different tamper resistance work factor environment.
Several dissimilar digital signature algorithms may be used to reduce
vulnerability from algorithm compromise, and subsets of multiple digital
signatures may be used to reduce the scope of any specific compromise.