  We suggest a categorification procedure for the SO(2N) one-variable
specialization of the two-variable Kauffman polynomial. The construction has
many similarities with the HOMFLYPT categorification: a planar graph formula
for the polynomial is converted into a complex of graded vector spaces, each of
them being the homology of a Z_2 graded differential vector space associated to
a graph and constructed using matrix factorizations. This time, however, the
elementary matrix factorizations are not Koszul; instead, they are convolutions
of chain complexes of Koszul matrix factorizations. We prove that the homotopy
class of the resulting complex associated to a diagram of a link is invariant
under the first two Reidemeister moves and conjecture its invariance under the
third move.
