Methods and system for providing security to critical systems connected to a computer network

A method for safeguarding a critical computing device connected to an external communication network, wherein the critical computing device either stores itself critical data or connected to a memory device storing critical data, the method comprising:

• receiving a set of data packets by a filtering module through the external communication network;
• processing of the data packets by the filtering module based on a set of rules and determining of a processed entropy value related to each of the data packets received;
• and
• fetching the entropy table by the filtering module from the memory unit and comparing it with the processed entropy value, and determining if the data packets received are malicious or non-malicious, and if the data packets are determined to be non-malicious data packets, forwarding the non-malicious data packets to the critical computing device;
• wherein the entropy table is having entropy values related to data packets regarding disorders in the data packets;
• and
• wherein the filtering module operates onto the data packets according to a network layer of a communication protocol, in the kernel space.

A non-transitory machine-readable storage medium comprising executable instructions that, when executed by one or more computing processors perform operations, the one or more computing processors are communicatively coupled to an external communication network and a critical computing device to enable transferring of data packets from the external communication network to the critical computing device after processing the data packets, the critical computing device either stores itself critical data or connected to a memory device storing critical data, the operations comprising:

• receiving a set of data packets through the external communication network;
• processing of the data packets based on a set of rules and determining of a processed entropy value related to each of the data packets received;
• and
• fetching the entropy table from a memory unit and comparing it with the processed entropy value, and determining if the data packets received are malicious or non-malicious, and if the data packets are determined to be non-malicious data packets, forwarding the non-malicious data packets to the critical computing device;
• wherein the entropy table is having entropy values related to data packets regarding disorders in the data packets;
• and
• wherein at least one of the processors operates onto the data packets according to a network layer of a communication protocol, in the kernel space.