Security layers of protection

Security layers of protection Also known as concentric rings of protection, a concept of providing multiple independent and overlapping layers of protection in depth. For security purposes, this may include various layers of protection such as countersurveillance, counterintelligence, physical security, and cyber security. 

In the case of malicious acts, the layers or rings of protection must be particularly robust because the adversaries are intentionally attempting to breach the protective features and can be counted on to use whatever means are available to be successful. This could include explosions or other initiating events that result in widespread common-cause failures. Some particularly motivated adversaries might commit suicide while attempting to breach the security layers of protection. 

The security system can be considered as layers of protection. Physical barriers and deterrents constitute not only the building stmcture itself, made up of walls, doors, windows, floor and a roof, but the yard around the building and probably a perimeter fence or wall. 

A complete security design includes these four concepts in layers of protection or a defense in depth arrangement. The most critical assets should be placed in the center of conceptual concentric levels of increasingly more stringent security measures. In the concept of rings of protection, the spatial relationship between the location ofthe target asset and the location ofthe physical countermeasures is important. 

In fact, the table did not reflect the economic evaluation of the pressure relief range after the optimization of technology. Because there is not yet accounting the security investment of protective layer, so temporarily ignore it. However, it can be seen from the table, only consider addition of the recovery rate, the reduction of the roadway excavation and maintenance costs, the optimized technical measures added value of 95.037 million yuan than the original program. Thus, the economy of optimized technical solutions is objective. 

A Center for Chemical Process Safety (CCPS) publication gives the following definition An IPL is a device, system or action which is capable of preventing a scenario from proceeding to its undesired consequence independent of the initiating event or the action of any other layer of protection associated with the scenario. The effectiveness and independence of an IPL must be auditable [12]. Discussions on layer of protection analysis (LOPA) were covered in Chapter V, so they are not repeated here. However, a few characteristic features of protection layers are presented. Similar to fault tolerance and security, this is also important so that the control system is always safe. As per lEC 61511 standard the core idea for integrated safety and security is defense-in-depth with independent layers of protection to reduce process risk. The strategy behind this is that the BPCS, critical... 

LOPA is a semi-specific method that can be used to assess the effectiveness of controls that have been put in place to mitigate urban security risks. LOPA offers a rather technical framework for performing such analyses. E.g. in Case3 one layer of protection could be the legal prohibition of selling alcohol in certain areas. A second layer of protection could be a number of social workers at the affected areas. LOPA can support the analysis of these protection layers. 

After the silica flour or soil mixture has set, add a layer of silica sand as a filter pack, then fill the remainder of the borehole with bentonite or a grout seal (Figure 5). Access lines may be run from the lysimeter reservoir through a protective PVC riser pipe to the land surface. A locking protective casing should be used to secure the abovegrade lysimeter components. If the lysimeter is used immediately after installation, it is necessary to purge any water used to prepare the siiica flour or soil slurry. Remove at least the water volume equivalent to approximately one third of that used to make slurry. 

Ideally, in a perfect world, all chemical facilities would be secured in a layered fashion (aka the barrier approach). Layered security systems are vital. Using the protection in-depth principle, requiring that an adversary defeat several protective barriers or security layers to accomplish its goal, chemical industry infrastructure can be made more secure. Protection in depth is a term commonly used by the military to describe security measures that reinforce one another, masking the defense mechanisms from the view of intruders, and allowing the defender time to respond to intrusion or attack. 

In chemical industry infrastructure security, protection in depth is used to describe a layered security approach. A protection-in-depth strategy uses several forms of security techniques and/or devices against an intruder and does not rely on one single defensive mechanism to protect infrastructure. By implementing multiple layers of security, a hole or flaw in one layer is covered by the other layers. An intruder will have to intrude through each layer without being detected in the process—the layered approach implies that no matter how an intruder attempts to accomplish his goal, he will encounter effective elements of the physical protection system. 

For example, as depicted in figure 9.1, an effective security layering approach requires that an adversary penetrate multiple, separate barriers to gain entry to a critical target at a chemical industry facility. As shown in figure 9.1, protection in depth (multiple layers of security) helps to ensure that the security system remains effective in the event of a failure or an intruder bypassing a single layer of security. 

Security can be thought of as a system of layers that protect the computer system that must be secured. The outer layer constitutes the physical security and the innermost layer constitutes the logical security. Figure 26.4 arranges these layers in a hierarchy structure. 

The droplet cell. Fig. 2(d), has uniform current distribution and shrunken dimensions that allow resistive electrolytes to be used [5]. This approach was developed for the use of pure water as an electrolyte as a means to mimic atmospheric corrosion, but it can be used with any electrolyte. An area of a flat sample is exposed through a hole in a piece of protective tape. Electroplater s tape is a very resistant tape with good adhesion that is useful for this and other masking applications in corrosion. If the hole in the tape is made with a round punch, the same punch can be used to make circular dots from pieces of filter paper. One such dot is placed securely into the exposed hole. A small (typically 10-20 gl) droplet of soluhon is placed on the filter paper using a calibrated pipette. This wet filter paper acts as the electrolyte. A piece of woven Pt mesh is placed on top of the wet filter paper, and a reference electrode is held against the back of the Pt counterelectrode. As mentioned, the small dimensions allow the use of even very pure water. This simulates atmospheric corrosion, in which a thin water layer forms on the surface. As in atmospheric corrosion, soluble species on the sample surface and pollutant gases in the air are dissolved into the water droplet, which provides some conductivity. This technique has been used... 

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