On symmetry of information and polynomial time invertibility

  • Luc Longpré
  • Osamu Watanabe
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 650)


Symmetry of information states that for two strings x and y, K(xy)=K(x)+K(y ¦ x)±O(log¦xy¦). We consider the statement of whether symmetry of information holds in a polynomial time bounded environment. Intuitively, this problem is related the complexity of inverting a polynomial time computable function. We give some evidence supporting this intuition, by proving the following relations:
  1. 1.

    If the polynomial time symmetry of information holds, then there is a polynomial time algorithm that computes the shortest description of a string for “almost all” strings.

  2. 2.

    If the polynomial time symmetry of information holds, then every polynomial time computable function is probabilistic polynomial time invertible for “almost all” strings in its domain.

  3. 3.

    If P=NP (i.e., every polynomial time computable function is polynomial time invertible), then the polynomial time symmetry of information holds.



Polynomial Time Polynomial Time Algorithm Kolmogorov Complexity Random String Probabilistic Polynomial Time 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Springer-Verlag Berlin Heidelberg 1992

Authors and Affiliations

  • Luc Longpré
    • 1
  • Osamu Watanabe
    • 2
  1. 1.Dept. of Computer ScienceNortheastern UniversityBostonUSA
  2. 2.Dept. of Computer ScienceTokyo Institute of TechnologyTokyoJapan

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