Explanation
A critical product of the gap analysis process is the implementation's requirements, which are the specifications and criteria that define the desired outcomes, capabilities, and functionalities of the ZTA. The implementation's requirements are derived from the gap analysis, which identifies the current state, the target state, and the gaps between them. The implementation's requirements help to guide the design, development, testing, and deployment of the ZTA, as well as the evaluation of its effectiveness and alignment with the business objectives and needs.
References =
Zero Trust Planning - Cloud Security Alliance, section "Scope, Priority, & Business Case" The Zero Trust Journey: 4 Phases of Implementation - SEI Blog, section "Second Phase: Assess" Planning for a Zero Trust Architecture: A Planning Guide for Federal ..., section "Gap Analysis"

Explanation
According to NIST, the key mechanisms for defining, managing, and enforcing policies in a ZTA are the policy decision point (PDP), the policy enforcement point (PEP), and the policy information point (PIP). The PDP is the component that evaluates the policies and the contextual data collected from various sources and generates an access decision. The PEP isthe component that enforces the access decision on the resource. The PIP is the component that provides the contextual data to the PDP, such as the user identity, the device posture, the network location, the resource attributes, and the environmental factors.
References =
Zero Trust Architecture Project - NIST Computer Security Resource Center, slide 9 What Is Zero Trust Architecture (ZTA)? - F5, section "Policy Engine" Zero Trust Frameworks Architecture Guide - Cisco, page 4, section "Policy Decision Point"

To ensure that only legitimate users can access Software as a Service (SaaS) or Platform as a Service (PaaS) in a Zero Trust framework, implementing robust authentication mechanisms is crucial. Enforcing Multi-Factor Authentication (MFA) and Single Sign-On (SSO) are effective strategies. MFA adds layers of security by requiring users to provide multiple pieces of evidence to verify their identity, making unauthorized access significantly more challenging. SSO simplifies the user experience by allowing users to access multiple services with one set of credentials while maintaining high security standards, particularly when combined with MFA. These measures align with the Zero Trust principle of "never trust, always verify," ensuring that access is granted only after thorough verification of the user's identity.

Explanation
Network access control (NAC) typically operates at layer 2, the data link layer, of the open systems interconnection (OSI) model. The data link layer is responsible for transferring data between adjacent nodes on a network, such as switches and endpoints. NAC operates at this layer by inspecting and controlling the access of devices to the network based on their MAC addresses, device profiles, security posture, and compliance status.
References = Certificate of Competence in Zero Trust (CCZT) - Cloud Security Alliance, Zero Trust Training (ZTT) - Module 6: Micro-segmentation

Explanation
Data sources are the ZT element that provide information that providers can use to keep policies dynamically updated. Data sources are the inputs that feed the policy engine and the policy administrator with the relevant data and context about the entities, resources, transactions, and environment in the ZTA. Data sources help to inform the policy decisionsand actions based on the current state and conditions of the ZTA. Data sources can include identity providers, device management systems, threat intelligence feeds, network monitoring tools, etc.
References = Certificate of Competence in Zero Trust (CCZT) - Cloud Security Alliance, Zero Trust Training (ZTT) - Module 3: ZTA Architecture and Components