Side-channel Attacks (Time)

[Shark8 <OneWingedShark@gmail.com>]

Considering the needs for a secure, verified security library [to 
replace OpenSSL] I was wondering about using the TASK construct in 
conjunction with DELAY UNTIL /OP_UPPERBOUND/* would be an acceptable 
countermeasure.

Psudeocode-ish Example:

task body Protocol is
   Upperbound : Time;
   Working    : Data;
begin
--...
   accept request ([...]) do
     Upperbound:= Clock + operation_length;
   end request;

   Working:= do_operation;
   delay until Upperbound;

   accept response ( Result : out Data )
     Result := Working;
   end response;
--...
end Protocol;


* OP_UPPERBOUND would be the the time the request was made plus the time 
needed to perform the [cryptographic] function.