[en] Based on the widely accepted assumption that the full gluon propagator becomes an infrared singular like (q²)^-2 at small momenta, the Schwinger-Dyson equation for the quark propagator, completed by the corresponding Slavnov-Taylor identity was investigated in a gauge-invariant way. Three and only three confinement-type solutions were found for the quark propagator in the infrared region. A close connection between quark confinement and chiral symmetry breaking was established. It is stated that the ghost degrees of freedom play an essential role in the dynamics of chiral symmetry breaking. (author) 22 refs