The article contains a misleading description of NP-hardness:
> Computing the Kolmogorov complexity for a sequence X of N bits length is an NP-hard problem, since the search space of possible programs producing any sequence of length N is growing exponentially with respect to the input size N
NP-hardness would actually mean that any NP problem, e.g. a traveling salesman problem, could be "reduced" within polynomial time to calculating the Kolmogorov Complexity of a given string.
> Computing the Kolmogorov complexity for a sequence X of N bits length is an NP-hard problem, since the search space of possible programs producing any sequence of length N is growing exponentially with respect to the input size N
NP-hardness would actually mean that any NP problem, e.g. a traveling salesman problem, could be "reduced" within polynomial time to calculating the Kolmogorov Complexity of a given string.