  This paper addresses the risk-minimization problem, with and without
mortality securitization, \`a la F\"ollmer-Sondermann for a large class of
equity-linked mortality contracts when no model for the death time is
specified. This framework includes the situation where the correlation between
the market model and the time of death is arbitrary general, and hence leads to
the case of a market model where there are two levels of information. The
public information which is generated by the financial assets, and a larger
flow of information that contains additional knowledge about a death time of an
insured. By enlarging the filtration, the death uncertainty and its entailed
risk are fully considered without any mathematical restriction.
  Our key tool lies in our optional martingale representation that states that
any martingale in the large filtration stopped at the death time can be
decomposed into precise orthogonal local martingales. This allows us to derive
the dynamics of the value processes of the mortality/longevity securities used
for the securitization, and to decompose any mortality/longevity liability into
the sum of orthogonal risks by means of a risk basis. The first main
contribution of this paper resides in quantifying, as explicit as possible, the
effect of mortality uncertainty on the risk-minimizing strategy by determining
the optimal strategy in the enlarged filtration in terms of strategies in the
smaller filtration. Our second main contribution consists of finding
risk-minimizing strategies with insurance securitization by investing in stocks
and one (or more) mortality/longevity derivatives such as longevity bonds. This
generalizes the existing literature on risk-minimization using mortality
securitization in many directions.
