Patent ID: 8719667

Claim:
A method of adding redundant data to a distributed data storage system, wherein said distributed data storage system stores a file of quantity M bits split in k blocks of a first predetermined quantity α bits, comprising devices connected to a network, the method comprising the following successive steps: adding a first predetermined number t of new devices for adding of redundant data, said first predetermined number being equal to at least two, each of said first predetermined number of new devices contacts a set of any existing devices of a second predetermined number d and obtains, from each of said existing devices of said set, a second predetermined quantity β bits of first redundant data in form of at least one code word being the result of a computation applied to said first predetermined quantity α bits of redundant data stored by each of said existing devices; obtaining, by each of said new devices, from each other new devices, a third predetermined quantity β′ bits of second redundant data in form of at least one code word being the result of a computation applied to all said first redundant data retrieved in the first step in form of at least one code word and stores third redundant data of said first predetermined quantity α bits in form of at least one code word being the result of a computation applied to all said first redundant data retrieved in the first step in form of at least one code word and all said second redundancy data in form of at least one code word; said second predetermined quantity β bits being different from said third predetermined quantity β′ bits, M and k being whole numbers greater than or equal to two, d being superior to k, α being superior or equal to M divided by k, and β and β′ being inferior to α.