• Real time monitoring of
safety-critical networks • Secure OT – IT bridge • Secure
cloud connectivity of critical
OT networks •
Database replication •
Data mining •
Trusted back-end and hybrid
cloud hosted solutions (private / public) • Secure data exchange for data marketplaces • Secure credential/ certificate provisioning • Secure cross-data base sharing • Secure printing from a less secure network to a high secure network (reducing print costs) • Transferring application and operating system updates from a less secure network to a high secure network • Time synchronization in highly secure networks •
File transfer •
Streaming video • Sending/receiving alerts or alarms from open to critical/confidential networks • Sending/receiving emails from open to critical/confidential networks • Government • Commercial companies
Usage Unidirectional network devices are typically used to guarantee information security or protection of critical digital systems, such as
Industrial control systems, from cyber attacks. While use of these devices is common in high security environments such as defense, where they serve as connections between two or more networks of differing security classifications, the technology is also being used to enforce one-way communications outbound from critical digital systems to untrusted networks connected to the
Internet. The physical nature of unidirectional networks only allows data to pass from one side of a network connection to another, and not the other way around. This can be from the "low side" or untrusted network, to the "high side" or trusted network, or vice versa. In the first case, data in the high side network is kept confidential and users retain access to data from the low side. Such functionality can be attractive if sensitive data is stored on a network which requires connectivity with the
Internet: the high side can receive Internet data from the low side, but no data on the high side are accessible to Internet-based intrusion. In the second case, a safety-critical physical system can be made accessible for online monitoring, yet be insulated from all Internet-based attacks that might seek to cause physical damage. In both cases, the connection remains unidirectional even if both the low and the high network are compromised, as the security guarantees are physical in nature. There are two general models for using unidirectional network connections. In the classical model, the purpose of the data diode is to prevent export of classified data from a secure machine while allowing import of data from an insecure machine. In the alternative model, the diode is used to allow export of data from a protected machine while preventing attacks on that machine. These are described in more detail below.
One-way flow to less secure systems Involves systems that must be secured against remote/external attacks from public networks while publishing information to such networks. For example, an election management system used with
electronic voting must make election results available to the public while at the same time it must be immune to attack. This model is applicable to a variety of
critical infrastructure protection problems, where protection of the data in a network is less important than reliable control and correct operation of the network. For example, the public living downstream from a
dam needs up-to-date information on the outflow, and the same information is a critical input to the control system for the
floodgates. In such a situation, it is critical that the flow of information be from the secure control system to the public, and not vice versa.
One-way flow to more secure systems The majority of unidirectional network applications in this category are in defense, and defense contractors. These organizations traditionally have applied
air gaps to keep classified data physically separate from any Internet connection. With the introduction of unidirectional networks in some of these environments, a degree of connectivity can safely exist between a network with classified data, and a network with an Internet connection. In the
Bell–LaPadula security model, users of a computer system can only create data at or above their own security level. This applies in contexts where there is a hierarchy of
information classifications. If users at each security level share a machine dedicated to that level, and if the machines are connected by data diodes, the Bell–LaPadula constraints can be rigidly enforced. == Benefits ==