Abstract: A method, performed by a user device, for proving retrievability (POR) of information includes: a1) exchanging credentials with a storing device and an auditing device to be used for communication between them; b1) encoding the information to be stored on the storing device; c1) initiating storing the encoded information on the storing device; d1) receiving correctness information, wherein the correctness information is secure and is generated based on the result of verification using unpredictable random information; and e1) validating the correctness information and unpredictable random information for proving retrievability of the stored information.

Abstract: A method, performed by a user device, for proving retrievability (POR) of information includes: a1) exchanging credentials with a storing device and an auditing device to be used for communication between them; b1) encoding the information to be stored on the storing device; c1) initiating storing the encoded information on the storing device; d1) receiving correctness information, wherein the correctness information is secure and is generated based on the result of verification using unpredictable random information; and e1) validating the correctness information and unpredictable random information for proving retrievability of the stored information.

Abstract: A method for proving retrievability (POR) of information is performed in a memory available to one or more computation devices, wherein credentials between a user device, a storing device and an auditing device between each pair of said devices are exchanged and used for communication between them. The method includes encoding information to be stored on the storing device by the user device or the auditing device, storing the encoded information on the storing device, verifying the correctness of the stored information by the auditing device using unpredictable random information, transmitting correctness information to the user device, the correctness information being secure and being generated based on the result of the verification by the auditing device, and validating the correctness information by the user device for proving retrievability of the stored information and the unpredictable random information.