Memorandum for Security Type That Is Associated with Each Level of the Open Systems Interconnect (osi) Model

Memorandum for Security Type That Is Associated with Each Level of the Open Systems Interconnect (OSI) Model

This memorandum explains the security type that is associated with the Open Systems Interconnect (OSI) Model. The memorandum will take each layer of the OSI model and apply to the security methods.

The first layer of OSI, the Physical Layer, associates with physical security and access control. "Wikipedia" (2006) stated, "The Physical layer defines all the electrical and physical specifications for devices. This includes the layout of pins, voltages, and cable specifications. Hubs, repeaters and network adapters are physical-layer devices." The major functions are physical connections activation and deactivation and data-unit transmission, such as cutting of cables and changing interface pins. Since this layer negotiates with physical components, the security types concentrate on the component protections. The main types are physical security and access control. Physical security refers to physical protections include keys, locks, access audit logs, server access authorization, and a Uninterrupted Power Supply (UPS). Logical security defines as access control and password protection.

The Data Link Layer transmits and receives packets on a specific medium across a network, including error detection and recovery, so the security emphasizes intrusion prevention. This layer defines the framing, addressing, and checking packets. The addressing scheme is the addresses (MAC address) that are hard-coded into the network cards. The security types are MAC-access-control lists, IEEE 802.1x protocol, Point-to-Point Protocol (PPP), and Virtual Private Networks (VPN). Falko Dressler (2005) indicated, "802.1x introduce two ports: the uncontrolled port allows authenticating a device and the controlled port allows an authenticated device to access LAN service." The security services of PPP include layer two frame format delimitation, error detection, and Link Control Protocol (LCP) for connection establishment. VPN makes sure the use of dedicated link and controlled route filter are safe.

The Network Layer defines the network addressing and routing structure of the internet, logical network layout, and computer interconnectivity. Since this layer delivers the data between two hosts, a firewall is required to protect the network. The firewall can scan the incoming and outgoing packets according to the security rules or criteria to prevent unauthorized accesses from hackers. Another security type is IPSec. The IPSec provides security for sensitive information transmission over unprotected networks. The IPSec encrypts and authenticates all traffics at the IP level to protect the messages sent through a path, including access control, connectionless integrity, data origin authentication, and data confidentiality.

The Transport Layer ensures reliability and error checking of the data delivery. Secure Socket Layer (SSL) is the security type at the Transport Layer. SSL is used for managing the security of a message transmission on the internet. SSL uses a public and private key encryption system and digital certificate. Since the layer responses for data delivery, the firewall is an option to reduce the risk from an attacker. The wireless security protocol at this layer uses Wireless Transport Layer Security (WTLS).

The Session Layer manages, establishes, and terminates communication connections. "Internet security systems" (2002) wrote, "Transmission Control Protocol (TCP) session hijacking is when a hacker takes over a TCP session between two machines." The Session Layer must prevent unwanted connections and make sure it is authentication". The authentication's methods can be applied at the Session Layer are SSL, Secure Shell (SSH), Kerberos, and IPSec. SSH allows login and execute commands on another workstation over a network. SSH uses a public and private key authentication system. Kerberos provides secure authentication over an insecure