Repeating this for all m blocks yields the original data. Not really sure. However, not sure about other operations. Mostly taking dot products. Not sure how it compares to other schemes.
Suggestion works best when number of pieces is small.
Each black node in the middle column computes the XOR of the nodes on the other end of its incoming edges. This process can be continued by adding more columns of redundant nodes that will in turn compute the XOR of their inputs. The result of this structure is that a large amount of redundant information about the original source nodes is computed. The edges between any two columns are specified by specific distributions. Once this process is completed, these bits may be distributed.