At Bletchley Park our old friend Tony Sale did the reconstruction of Colossus,see original machine in the link.
A massively parallel special purpose computer its speed was equivalent to a 1 MHz Pentium PC, achieved with 100s of valves and relays
Colossus cracked the Lorentz keys in 20 minutes.
Now at the National Museum of Computing near Bletchley Park in the UK
Jon