Abstract: A cryptographic method implemented on an electronic communication network interconnecting a plurality of terminals represents funds in a way that is secure at the issuer and secure when funds move from payer to payee and back to the issuer. The cryptographic method mints, issues, pays and redeems funds when transactions are done over the network with the flow and transaction of funds being controlled by an issuer. The method implements electronic money acquisition, transfer of money between users in an unrestricted way and in a way where fraud is impossible cryptographically, and redemption of electronic money to correct real money bank accounts. Funds are handled so that their representation enables the issuer to treat the representation as a physical monetary instrument equivalent to notes or coins.

Abstract: A solution to the general problem of Secure Storage and Retrieval of Information (SSRI) guarantees that also the process of storing the information is correct even when some processors fail. A user interacts with the storage system by depositing a file and receiving a proof that the deposit was correctly executed. The user interacts with a single distinguished processor called the gateway. The mechanism enables storage in the presence of both inactive and maliciously active faults, while maintaining (asymptotical) space optimailty. This mechanism is enhanced with the added requirement of confidentiality of information; i.e., that a collusion of processors should not be able to learn anything about the information. Also, in this case space optimality is preserved.