Ada Resource Association

The recent introduction of multicore architectures has caused a surprising amount of uproar. Multiprocessing has been around for decades. The original CDC 6000, for instance, was an interestingly designed multiprocessor machine first put into use in the early 1960s.

Another important player in multiprocessing is Ada. Even the original Ada 83 version of the language has a well-developed notion of multithreading (termed “tasking” in Ada) with high-level constructs that are easy to use and analyze. The subsequent Ada 95 and Ada 2005 versions of the language substantially improved and extended this functionality, and decades of experience have been accumulated in using Ada to deal with the problem of writing programs that run effectively on machines using more than one processor.

In November of 2007, the National Museum of Computing sponsored an historical code-breaking competition to celebrate the rebuild of Colossus Mark 2 at Bletchley Park. Colossus, the first programmable digital computer, was used in WWII to crack the codes created by the Lorenz cipher machines used by the German High Command. Programmers and code breakers were invited to try to beat the rebuilt Colossus in cracking the 1938 Lorenz SZ42 encrypted message.

Using Ada, IT security specialist, Joachim Schüth, was able to decipher the code and beat Colossus. In the following interview, Joachim explains why he started working with Ada, his impressions of the language, and why it was the perfect choice for the challenge.