  The precise design of a system may be considered a trade secret which should
be protected, whilst at the same time component manufacturers are sometimes
reluctant to release full test data (perhaps only providing mean time to
failure data). In this situation it seems impractical to both produce an
accurate reliability assessment and satisfy all parties' privacy requirements.
However, we present recent developments in cryptography which, when combined
with the recently developed survival signature in reliability theory, allows
almost total privacy to be maintained in a cryptographically strong manner in
precisely this setting. Thus, the system designer does not have to reveal their
trade secret design and the component manufacturer can retain component test
data in-house.
