Brief outline of reversible computing

• Reversible computer: given outputs can calculate inputs by running program backwards

  
  

• Fredkin and Toffoli $\approx 1980$

  
  

• Applications? - not really

  
  

  
  Using roll back to: detect (transient) errors (critical systems)
  
  
  Security - anti hacking roll back
  
  
  Speculative Execution in multiprocessors
  

• Quantum computing

  The mathematical view, quantum computing is the complex number extension of reversible computing

• Lowest possible power consumption - less cooling problems