Network security based on device identifiers and network addresses

A method for controlling communication in a computer network managed by an organization, the method comprising:

• evaluating a network communication from a first computing device, wherein the first computing device is connected to a first network and uses a source network address, by:
• determining whether the source network address is included in a list of trusted network addresses;
• when the source network address is not included in the list of trusted network addresses, disallowing the network communication on the first network;
• when the source network address is included in the list of trusted network addresses,
• receiving data representing a non-modifiable device identifier of the first computing device;
• determining whether the device identifier is included in a list of trusted device identifiers;
• and
• when the device identifier is included in the list of trusted device identifiers, allowing the network communication on the first network;
• receiving an indication of a white list of trusted network addresses that includes, for each of the trusted network addresses, one or more indications of allowable communication properties;
• determining a first communication property that is associated with the network communication;
• determining a second communication property that is an allowable communication property specified by an entry in the white list that corresponds to the source network address;
• evaluating the network communication with respect to the white list, by determining whether or not the first communication property is encompassed by the second communication property;
• in response to determining that the first communication property is not encompassed by the second communication property, disallowing the network communication;
• in response to determining that the first communication property is encompassed by the second communication property, allowing the network communication;
• determining that a first packet that is transmitted by the first device is associated with an authorized network address and an authorized non-modifiable device identifier;
• allowing multiple packets received from the first device subsequent to the first packet, wherein the multiple packets are allowed based on source network addresses and without any evaluation of non-modifiable device identifiers;
• and
• after passage of a determined time interval or a determined number of packets, requiring the first device to again provide its non-modifiable device identifier to authorize further communication,
• wherein the first computing device is configured to execute a secure boot process that loads and executes only trusted code, wherein the trusted code disallows any modification of hardware identifiers of the first computing device including the non-modifiable device identifier.

A non-transitory computer-readable medium that stores instructions that are configured, when executed by a computer processor, to perform a method for controlling communication in a computer network managed by an organization, the method comprising:

• evaluating a network communication from a first computing device, wherein the first computing device is connected to a first network and uses a source network address, by:
• determining whether the source network address is included in a list of trusted network addresses;
• when the source network address is not included in the list of trusted network addresses, disallowing the network communication on the first network;
• when the source network address is included in the list of trusted network addresses,
• receiving data representing a non-modifiable device identifier of the first computing device;
• determining whether the device identifier is included in a list of trusted device identifiers;
• and
• when the device identifier is included in the list of trusted device identifiers, allowing the network communication on the first network;
• receiving an indication of a white list of trusted network addresses that includes, for each of the trusted network addresses, one or more indications of allowable communication properties;
• determining a first communication property that is associated with the network communication;
• determining a second communication property that is an allowable communication property specified by an entry in the white list that corresponds to the source network address;
• evaluating the network communication with respect to the white list, by determining whether or not the first communication property is encompassed by the second communication property;
• in response to determining that the first communication property is not encompassed by the second communication property, disallowing the network communication;
• and
• in response to determining that the first communication property is encompassed by the second communication property, allowing the network communication;
• and
• randomly audits packets received at a network interface by:
• randomly selecting a first packet;
• determining whether the source network address and the non-modifiable device identifier associated with the first packet are both authorized;
• allowing multiple packets received from the first device subsequent to the first packet without verifying a non-modifiable device identifier;
• randomly selecting a second packet received after the multiple packets;
• determining whether the source network address and the non-modifiable device identifier are both authorized;
• and
• determining whether the source network address and the non-modifiable device identifier associated with the second packet are both authorized,
• wherein the first computing device is configured to execute a secure boot process that loads and executes only trusted code, wherein the trusted code disallows any modification of hardware identifiers of the first computing device including the non-modifiable device identifier.