Bytecode Verification
Bytecode verification checks that:
-  The file is correctly formatted
 -  The parameter stack will not overflow or underflow
 -  Bytecode instructions use the correct types
 -  No invalid type conversions are performed
 -  No unauthorised member access is performed (through private or protected fields and methods).
 -  Register accesses follow the legal conventions
 
Common problems
-  Insecure Java implementation (e.g. type checking)
 -  Inappropriate security policy