Chapter 4: Network Security
Hybrid cloud
A combination of public cloud storage and private cloud storage where some critical data resides in the enterprise's private cloud while other data is stored and accessible from a public cloud storage provider.
Cloud computing
A model for enabling ubiquitous, convenient, on-demand network access to a shared pool of configurable computing resources (e.g., networks, servers, storage, applications, and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction. NIST 800-145
Application programming interface (API)
A set of routines, standards, protocols, and tools for building software applications to access a web-based software application or web tool.
Protocols
A set of rules (formats and procedures) to implement and control some type of association (that is, communication) between systems. NIST SP 800-82 Rev. 2
Community cloud
A system in which the cloud infrastructure is provisioned for exclusive use by a specific community of consumers from organizations that have shared concerns (e.g., mission, security requirements, policy and compliance considerations). It may be owned, managed and operated by one or more of the organizations in the community, a third party or some combination of them, and it may exist on or off premises. NIST 800-145
VLAN
A virtual local area network (VLAN) is a logical group of workstations, servers, and network devices that appear to be on the same LAN despite their geographical distribution.
VPN
A virtual private network (VPN), built on top of existing networks, that can provide a secure communications mechanism for transmission between networks.
WLAN
A wireless area network (WLAN) is a group of computers and devices that are located in the same vicinity, forming a network based on radio transmissions rather than wired connections. A Wi-Fi network is a type of WLAN.
Internet Control Message Protocol (ICMP)
An IP network protocol standardized by the Internet Engineering Task Force (IETF) through RFC 792 to determine if a particular service or host is available.
Man-in-the-Middle
An attack where the adversary positions himself in between the user and the system so that he can intercept and alter data traveling between them. Source: NISTIR 7711
Payment Card Industry Data Security Standard (PCI DSS)
An information security standard administered by the Payment Card Industry Security Standards Council that applies to merchants and service providers who process credit or debit card transactions.
Broadcast
Broadcast transmission is a one-to-many (one-to-everyone) form of sending internet traffic.
Software
Computer programs and associated data that may be dynamically written or modified during execution. NIST SP 80--37 Rev. 2
Encapsulation
Enforcement of data hiding and code hiding during all phases of software development and operational use. Bundling together data and methods is the process of encapsulation; its opposite process may be called unpacking, revealing, or using other terms. Also used to refer to taking any set of data and packaging it or hiding it in another data structure, as is common in network protocols and encryption.
Spoofing
Faking the sending address of a transmission to gain illegal entry into a secure system. CNSSI 4009-2015
Fragment attack
In a fragment attack, an attacker fragments traffic in such a way that a system is unable to put data packets back together.
Transport Control Protocol/Internet Protocol (TCP/IP) Model
Internetworking protocol model created by the IETF, which specifies four layers of functionality: Link layer (physical communications), Internet Layer (network-to-network communication), Transport Layer (basic channels for connections and connectionless exchange of data between hosts), and Application Layer, where other protocols and user applications programs make use of network services.
Microsegmentation
Part of a zero-trust strategy that breaks LANs into very small, highly localized zones using firewalls or similar technologies. At the limit, this places firewall at every connection point.
Oversized Packet Attack
Purposely sending a network packet that is larger than expected or larger than can be handled by the receiving system, causing the receiving system to fail unexpectedly.
Zero Trust
Removing the design belief that the network has any trusted space. Security is managed at each possible level, representing the most granular asset. Microsegmentation of workloads is a tool of the model.
Packet
Representation of data at Layer 3 of the Open Systems Interconnection (OSI) model.
Internet Protocol (IPv4)
Standard protocol for transmission of data from source to destinations in packet-switched communications networks and interconnected systems of such networks. CNSSI 4009-2015
Byte
The byte is a unit of digital information that most commonly consists of eight bits.
Software as a Service (SaaS)
The cloud customer uses the cloud provider's applications running within a cloud infrastructure. The applications are accessible from various client devices through either a thin client interface, such as a web browser or a program interface. The consumer does not manage or control the underlying cloud infrastructure including network, servers, operating systems, storage, or even individual application capabilities, with the possible exception of limited user-specific application configuration settings. Derived from NIST 800-145
Public cloud
The cloud infrastructure is provisioned for open use by the general public. It may be owned, managed, and operated by a business, academic, or government organization, or some combination of them. It exists on the premises of the cloud provider. NIST SP 800-145
Zenmap
The graphical user interface (GUI) for the Nmap Security Scanner, an open-source application that scans networks to determine everything that is connected as well as other information.
File Transfer Protocol (FTP)
The internet protocol (and program) used to transfer files between hosts.
Bit
The most essential representation of data (zero or one) at Layer 1 of the Open Systems Interconnection (OSI) model.
De-encapsulation
The opposite process of encapsulation, in which bundles of data are unpacked or revealed.
Private cloud
The phrase used to describe a cloud computing platform that is implemented within the corporate firewall, under the control of the IT department. A private cloud is designed to offer the same features and benefits of cloud systems, but removes a number of objections to the cloud computing model, including control over enterprise and customer data, worries about security, and issues connected to regulatory compliance.
Hardware
The physical parts of a computer and related devices.
Denial-of-Service (DoS)
The prevention of authorized access to resources or the delaying of time-critical operations. (Time-critical may be milliseconds or it may be hours, depending upon the service provided.) Source: NIST SP 800-27 Rev A
Payload
The primary action of a malicious code attack.
Encryption
The process and act of converting the message from its plaintext to ciphertext. Sometimes it is also referred to as enciphering. The two terms are sometimes used interchangeably in literature and have similar meanings.
Infrastructure as a Service (IaaS)
The provider of the core computing, storage and network hardware and software that is the foundation upon which organizations can build and then deploy applications. IaaS is popular in the data center where software and servers are purchased as a fully outsourced service and usually billed on usage and how much of the resource is used.
Simple Mail Transport Protocol (SMTP)
The standard communication protocol for sending and receiving emails between senders and receivers.
Platform as a Service (PaaS)
The web-authoring or application development middleware environment that allows applications to be built in the cloud before they're deployed as SaaS assets.
Domain Name Service (DNS)
This acronym can be applied to three interrelated elements: a service, a physical server and a network protocol.
