Patent ID: 9286487
Filing Date: 2016-03-15
CPC Classification: G06F,H04L

Claim Text:
1. A method for protecting confidentiality of a file distributed and stored at a plurality of storage service providers, comprising performing at a computing means of a user device, the steps of: inputting a security parameter n, segmenting the file in n chunks S choosing n verifying that the vectors a computing n linear combinations C for i=1, . . . , n, wherein each of the combinations C i is computed by the computing means using all of the n chunks S 1 , . . . , S n of the file, choosing n storage service providers O generating n file identifiers ID′ transmitting and storing the combination C storing the file identifier ID′ storing the set of coefficients a wherein said choosing n 2 coefficients a ij for i=1, . . . , n and j=1, . . . , n, comprises: randomly choosing said n verifying that the vectors for a randomly choosing n super-coefficients a′ computing a linear over-combination OC′=a′ storing the over-combination OC′ and the coefficients a′ and wherein said storing the set of coefficients a i1 , . . . , a in , so that it can be re-associated with the combination C i , for i=1, . . . , n, comprises: storing the set of coefficients a storing a permutation (σ) enabling to re-associate the set of coefficients a