  Maximum-distance separable (MDS) array codes with high rate and an optimal
repair property were introduced recently. These codes could be applied in
distributed storage systems, where they minimize the communication and disk
access required for the recovery of failed nodes. However, the encoding and
decoding algorithms of the proposed codes use arithmetic over finite fields of
order greater than 2, which could result in a complex implementation.
  In this work, we present a construction of 2-parity MDS array codes, that
allow for optimal repair of a failed information node using XOR operations
only. The reduction of the field order is achieved by allowing more parity bits
to be updated when a single information bit is being changed by the user.
