Data authentication in distributed networks

A computer-implemented method for authenticating data of a distributed network, the distributed network comprising at least one application subnet, the method comprising:

• regularly computing a digest of a unit accumulator,
• wherein an application subnet in the distributed network comprises a plurality of nodes, wherein each of the plurality of nodes of the application subnet is configured to run an assigned set of two or more computational units, wherein the two or more computational units are pieces of software that comprise their own unit state and wherein the assigned set of the two or more computational units is replicated across the application subnet by individually executing on each node, by the two or more computational units of the assigned set running on each node, computations in a deterministic and replicated manner across the application subnet, and
• wherein the digest of the unit accumulator is regularly computed by each of the computational units of the application subnet, and the unit accumulator comprises a representation of the unit state of the respective computational unit, wherein accumulator elements of the unit accumulator comprise computational results of the respective computational unit;
• regularly writing the digest of the unit accumulator as unit variable into the corresponding accumulator element of the application subnet accumulator;
• issuing a request to a node of the application subnet for a computational result of one of the computational units of the application subnet;
• receiving, from the node to which the request is issued, an application subnet certificate, a witness of the application subnet accumulator, a witness of the unit accumulator and the requested computational result as response to the request;
• verifying the digest of the application subnet accumulator by means of the application subnet certificate;
• verifying the accumulator element of the respective computational unit by recalculating the digest of the application subnet accumulator by means of the witness of the application subnet accumulator;
• and
• verifying the requested computational result by recalculating the digest of the unit accumulator by means of the witness of the unit accumulator.

A distributed network comprising:

• at least one application subnet, wherein the application subnet comprises a plurality of nodes, wherein each of the plurality of nodes of the application subnet is configured to run an assigned set of two or more computational units, wherein the two or more computational units are pieces of software that comprise their own unit state and wherein the assigned set of the two or more computational units is replicated across the application subnet by individually executing on each node, by the two or more computational units of the assigned set running on each node, computations in a deterministic and replicated manner across the application subnet, the network being configured to
• regularly compute, by the plurality of nodes of the application subnet, a digest of an application subnet accumulator, the application subnet accumulator comprising for each of the computational units of a respective application subnet an assigned accumulator element as unit variable;
• regularly execute, by the nodes of the application subnet, a joint signature on the digest of the application subnet accumulator, thereby producing an application subnet certificate;
• regularly compute, by each of the computational units of the application subnet, a digest of a unit accumulator, the unit accumulator comprising a representation of the unit state of the respective computational unit, wherein accumulator elements of the unit accumulator comprise computational results of the respective computational unit;
• and
• regularly write the digest of the unit accumulator as unit variable into the corresponding accumulator element of the application subnet accumulator.

A computer program product comprising a non-transitory computer readable storage medium having program instructions embodied therewith, the program instructions executable by one or more processors to perform a method comprising:

• regularly computing, by a plurality of nodes of an application subnet in a distributed network, a digest of an application subnet accumulator,
• wherein each of the plurality of nodes of the application subnet is configured to run an assigned set of two or more computational units, wherein the two or more computational units are pieces of software that comprise their own unit state and wherein the assigned set of the two or more computational units is replicated across the application subnet by individually executing on each node, by the two or more computational units of the assigned set running on each node, computations in a deterministic and replicated manner across the application subnet, and
• wherein the application subnet accumulator comprises for each of the computational units of a respective application subnet an assigned accumulator element as unit variable;
• and
• regularly executing a joint signature on the digest of the application subnet accumulator, thereby producing an application subnet certificate;
• regularly computing, by each of the computational units of the application subnet, a digest of a unit accumulator, the unit accumulator comprising a representation of the unit state of the respective computational unit, wherein accumulator elements of the unit accumulator comprise computational results of the respective computational unit;
• and
• regularly writing the digest of the unit accumulator as unit variable into the corresponding accumulator element of the application subnet accumulator.