LAYERED CODING TECHNIQUES FOR DATA STORAGE

Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for skewed orthogonal coding techniques. In one aspect, a method includes receiving a block of data comprising a plurality of data chunks. One or more rows of word code chunks are generated using a first error-correcting code in systematic form and the plurality of data chunks. For each row of a plurality of rows of the data chunks, one or more row code chunks for the row are generated using a second error-correcting code in systematic form and the data chunks of the row. The rows of data chunks and the row code chunks and the rows of word code chunks are stored.