Abstract: Erasure encoded fragments are originally generated by applying an erasure encoding scheme to a data file. An erasure encoded fragment is subsequently generated directly from previously generated erasure encoded fragments or by reconstructing the original data file and then erasure encoding the reconstructed data file. The integrity or fidelity of such a subsequently generated erasure encoded fragment is verified by newly generating an error detection code, such as but not limited to a checksum, for the subsequently generated erasure encoded fragment, and comparing that subsequently error detection code against an error detection code previously generated for a previous or original version of the erasure encoded fragment. Each error detection code is preferably stored in association with its corresponding erasure encoded fragment and with one or more other erasure encoded fragments. Thus, each error detection code is saved in at least two locations.

Abstract: Erasure encoded fragments may be originally generated by applying an erasure encoding scheme to a data file. An erasure encoded fragment may be subsequently generated directly from previously generated erasure encoded fragments or by reconstructing the original data file and then erasure encoding the reconstructed data file. The integrity or fidelity of such a subsequently generated erasure encoded fragment may be verified by newly generating an error detection code, such as but not limited to a checksum, for the subsequently generated erasure encoded fragment, and comparing that subsequently generated error detection code against an error detection code previously generated for a previous or original version of the erasure encoded fragment. Each error detection code is preferably stored in association with its corresponding erasure encoded fragment and with one or more other erasure encoded fragments. Thus, each error detection code is saved in at least two locations.