Key distribution for a physical unclonable encryption system

A non-transitory computer readable medium comprising instructions which, when a program is executed by a computer of computer network cause the computer of computer network to perform the method for distributing symmetric encryption keys in a communication system comprising a plurality of nodes, wherein each of the nodes comprises a printing device configured for generating at least one encryption key for encrypting data based on changing printer control setting and printer job, wherein each node comprises information about possible printer control settings and possible printer jobs, the method comprising the following steps:

• a) providing an initial session key information via at least one secure channel to each node, wherein the initial session key information comprises an initial printer control setting and an initial printer job setting, wherein the initial session key information is different for each node;
• b) providing as a one-time pad an initial session key package to each of the nodes encrypted with the respective node's initial session key information, wherein the initial session key package comprises a plurality of items of first session key information for communication of the respective receiving node with the other nodes of the communication system, wherein any two nodes have a common item of first session key information;
• c) generating at each node second session key information for each of the other nodes, wherein the second session key information comprises a second printer control setting and a second printer job setting, wherein the second session key information generated by the respective node for the respective other nodes is different for each of the other nodes;
• d) sending a message from one of the nodes to another one of the nodes, wherein the message is encrypted with the first session key information for communication between said node and said another one of the nodes, wherein the message comprises the second session key information generated by the node sending the message for the node receiving the message such that the node sending the message and the node receiving the message are able for encrypted communication with each other.

A communication system comprising:

• a plurality of nodes, wherein each of the nodes comprises a printing device configured for generating at least one encryption key for encrypting data based on changing printer control setting and printer job, wherein each node comprises information about possible printer control settings and possible printer jobs, wherein the communication system is configured for providing an initial session key information via at least one secure channel to each node, wherein the initial session key information comprises an initial printer control setting and an initial printer job setting, wherein the initial session key information is different for each node, wherein the communication system further comprises at least one center hub configured for providing as a one-time pad an initial session key package to each of the nodes encrypted with the respective node's initial session key information, wherein the initial session key package comprises a plurality of items of first session key information for communication of the respective receiving node with the other nodes of the communication system, wherein any two nodes have a common item of first session key information, wherein each of the nodes is configured for generating at each node second session key information for each of the other nodes, wherein the second session key information comprises a second printer control setting and a second printer job setting, wherein the second session key information generated by the respective node for the respective other nodes is different for each of the other nodes, wherein each of the nodes is configured for sending a message from one of the nodes to another one of the nodes, wherein the message is encrypted with the first session key information for communication between said node and said another one of the nodes, wherein the message comprises the second session key information generated by the node sending the message for the node receiving the message such that the node sending the message and the node receiving the message are able for encrypted communication with each other.

An apparatus for distributing symmetric encryption keys in a communication system comprising a plurality of nodes, wherein each of the nodes comprises a printing device configured for generating at least one encryption key for encrypting data based on changing printer control setting and printer job, wherein each node comprises information about possible printer control settings and possible printer jobs, the apparatus comprising

• a memory storing instructions;
• and
• a processor configured to:
• a) providing an initial session key information via at least one secure channel to each node, wherein the initial session key information comprises an initial printer control setting and an initial printer job setting, wherein the initial session key information is different for each node;
• b) providing as a one-time pad an initial session key package to each of the nodes encrypted with the respective node's initial session key information, wherein the initial session key package comprises a plurality of items of first session key information for communication of the respective receiving node with the other nodes of the communication system, wherein any two nodes have a common item of first session key information;
• c) generating at each node second session key information for each of the other nodes, wherein the second session key information comprises a second printer control setting and a second printer job setting, wherein the second session key information generated by the respective node for the respective other nodes is different for each of the other nodes;
• d) sending a message from one of the nodes to another one of the nodes, wherein the message is encrypted with the first session key information for communication between said node and said another one of the nodes, wherein the message comprises the second session key information generated by the node sending the message for the node receiving the message such that the node sending the message and the node receiving the message are able for encrypted communication with each other.