Executive Order (EO) 14028, Improving the Nation’s Cybersecurity, directs the National Institute of Standards and Technology (NIST) to publish guidance on practices for software supply chain security. EO 14028 Section 4e contains ten (10) subsections, each of which specifies actions or outcomes for software producers, such as Commercial-Off-The-Shelf (COTS) product vendors, Government-Off-The-Shelf (GOTS) software developers, contractors, and other custom software developers. 

Accordingly, Secure Software Development Practices (SSDP) should be integrated throughout software life cycles for three (3) reasons:

1. To reduce the number of vulnerabilities in released software;
2. To reduce the potential impact of the exploitation of undetected or unaddressed vulnerabilities; and
3. To address the root causes of vulnerabilities to prevent recurrences.

NIST SP 800-218 addresses EO 14028 Section 4e from a software producer viewpoint. The software producers are the ones who implement SSDF practices. EO 14028 Section 4k explains that federal agencies will need to comply with NIST guidelines. In this context, federal agencies are software  purchasers, not software producers, so additional guidance from the US Government is needed to address EO 14028 Section 4e from a software purchaser viewpoint. However, when a federal agency (purchaser) acquires software or a product containing software, the agency is required to receive attestation from the software producer that the software’s development complies with US Government-specified secure software development practices.

It is expected that Federal agencies will request artifacts from the software producer that support its attestation of conformity with the SSDP described in EO 14028 Section 4e subsections (i), (iii) and (iv).

Software providers will invariably be impacted by EO 14028 due to trickle-down requirements. While a software provider may not categorize itself as a "Federal contractor" or a "Defense contractor" since it does not directly sell to the US Government, it will still get caught up in requirements that flow down from its customers that do sell products or provide services to the US Government. This is just the reality of how the Federal Acquisition Regulation (FAR) and Defense Acquisition Regulations System (DFARS) clauses work - those clauses trickle down throughout the supply chain.

With EO 14028, it is specifically targeted at America's supply chain security. This is where it will be nearly impossible for software providers to avoid:

• Implementing Secure Software Development Practices (SSDP); and
• Having the artifacts (e.g., evidence) that the software provider (including its developers and architects) have implemented the SSDP throughout the lifecycle of the applications, service and/or process.

NIST defined the following minimum recommendations for Federal agencies as they acquire software or a product containing software. These recommendations are intended to assist Federal agencies and software producers in communicating clearly with each other regarding secure software development artifacts, attestation, and conformity:

1. Use the SSDF’s terminology and structure to organize communications about secure software development requirements. This enables all software producers to use the same lexicon when attesting to conformity for federal agencies. Software producers can map their secure development methodology to the SSDF’s secure software development practices or associated informative references.
2. Require attestation to cover secure software development practices performed as part of processes and procedures throughout the software life cycle. With the highly dynamic nature of software today, attesting to how things were and are done on an ongoing basis (processes and procedures) is typically more valuable than attesting to how things were done for a specific software release generated by one instance of those processes. This is especially true for post-release practices such as vulnerability disclosure and response, where processes might not yet have been performed for the latest release.
3. Accept first-party attestation of conformity with SSDF practices unless a risk-based approach determines that second or third-party attestation is required. First-party attestation is recommended for meeting the EO 14028 requirements. This is consistent with the guidance in NIST SP 800-161 Rev. 1 (Second Draft), which states in Section 3.1.2: “There are a variety of acceptable validation and revalidation methods, such as requisite certifications, site visits, third-party assessment, or self-attestation. The type and rigor of the required methods should be commensurate to the criticality of the service or product being acquired and the corresponding assurance requirements.”
4. When requesting artifacts of conformance, request high-level artifacts. The software producer should be able to trace the practices summarized in the high-level artifacts to the corresponding low-level artifacts that are generated by those practices. Asking for low-level artifacts for a particular software release is not recommended for meeting the requirements of EO 14028, but may be needed to meet other agency requirements. Reasons for avoiding low-level artifacts include the following:
• Low-level artifacts provide a snapshot in time of only a small aspect of secure software development, whereas high-level artifacts can provide a big-picture view of how secure software development is performed.
• Artifacts should address the needs of the audience receiving them, thus providing the necessary information in a usable format for that audience. Understanding low-level artifacts require the agency to expend considerable technical resources and expertise in analyzing them and determining how to consider them within the context of the broader secure software development practices.
• Low-level artifacts often contain intellectual property or other proprietary information, or details that attackers could use for hostile purposes, so accepting low-level artifacts gives the agency additional sensitive information to protect. These minimum recommendations apply to attestation for all software within the scope of this guidance procured by federal agencies and they should be part of each agency’s processes. The recommendations are not intended to replace more stringent requirements for secure software development that federal agencies may have.