QBOM vs CBOM: how the quantum and cryptographic BOMs differ
The two are often mentioned together and sometimes used interchangeably. They answer different questions, and knowing which is which makes both easier to build.
- A CBOM inventories cryptographic assets: algorithms, keys, protocols and certificates.
- A QBOM, as CERT-In defines it, documents components related to quantum computing and quantum-safe cryptography.
- The QBOM's Cryptographic Asset element points to the CBOM, so the CBOM comes first.
- In migration practice, the QBOM adds exposure and readiness attributes to the CBOM's inventory.
- Indian policy documents, from CERT-In to DST and RBI, lean on the CBOM as the starting point.
The short answer
A CBOM tells you what cryptography you use and where. A QBOM tells you about quantum-related and quantum-safe components and, in practice, how exposed and how ready your cryptography is for the quantum era. CERT-In describes the two as together forming a unified foundation for securing cryptographic systems [1]. For the CBOM cluster's version of this comparison, see CBOM vs QBOM.
Side by side
| CBOM | QBOM | |
|---|---|---|
| CERT-In definition | Inventory of cryptographic assets, with minimum elements by asset type in Table 9 [1] | "Focuses on components related to quantum computing and quantum-safe cryptography" (section 8.1) [1] |
| Minimum elements | Algorithms, keys, protocols and certificates, each with its own fields (for example primitive, mode, key size, cipher suites, signature algorithm) [1] | Model name, version, vendor and origin, licence information, cryptographic asset, communication protocol, hardware, software dependencies, environmental impact, vulnerabilities, attestations [1] |
| Core question | What cryptography is in use, and where? | Which components are quantum-related or quantum-safe, and how ready are we? |
| Migration-practice additions | Usually none; it is a factual inventory | Quantum-vulnerable flag, data lifetime, exposure, priority tier, target algorithm, migration status |
| Typical owner | Security engineering, PKI and platform teams | PQC programme owner with service owners |
| Format | CycloneDX cryptographic assets [2] | CycloneDX or SPDX; CERT-In recommends both formats [1] |
Why the CBOM comes first
The QBOM's Cryptographic Asset element is described using the CBOM asset types [1], so a QBOM without a CBOM has an empty core. Indian policy work reflects the same ordering. The TEC technical report on PQC migration recommends a Cryptographic Bill of Materials to represent discovered cryptographic components [3]. The DST task force recommends common procurement requirements with mandatory CBOMs [4]. RBI's Q-SAFE committee, formed in May 2026, is asked to assess the financial sector's cryptographic vulnerabilities through a CBOM evaluation [5].
OWASP CycloneDX lists post-quantum readiness among the main CBOM use cases [2]. In other words, the CBOM is the raw material and the QBOM is where it becomes a readiness view.
Where they overlap
- Both record cryptographic assets. Keep one source of truth for each asset and reference it from both views, rather than maintaining two copies.
- Both include vulnerabilities; CERT-In expects CBOM/QBOM data to be cross-referenced with VEX status [1].
- Both must be kept current and protected with encryption, access control and integrity mechanisms [1].
Where they differ in practice
- Components beyond cryptography. CERT-In's QBOM covers hardware such as processors, simulators and networking components, and environmental impact such as energy consumption [1]. These matter for quantum devices and have no CBOM equivalent.
- Judgement. A CBOM is largely factual. The quantum-exposure view adds judgements about data lifetime and priority that must be owned and reviewed; see Quantum risk assessment.
- Lifecycle. A CBOM changes with every release. The QBOM's readiness attributes change as migration progresses; see QBOM management.
Which to build first
Build the CBOM first for your critical services (see What is a CBOM?), then extend it into a QBOM with CERT-In's Table 8 elements and exposure attributes (see How to build a QBOM).
How IntelliXBOM helps
IntelliXBOM keeps CBOM and QBOM data together in CycloneDX or SPDX, so each cryptographic asset is recorded once and referenced from both views. It validates both against CERT-In's required fields, keeps version history and diffs, and correlates assets with vulnerabilities, VEX decisions and business services.
Frequently asked questions
Do I need both a CBOM and a QBOM?
CERT-In's guidelines treat them as complementary, and its QBOM includes a cryptographic asset element described using CBOM fields. Most organisations build the CBOM first and extend it into a QBOM for quantum readiness.
Can one CycloneDX file hold both?
Yes. CycloneDX 1.6 represents cryptographic assets as components with crypto properties, alongside software, hardware and firmware components, so CBOM and QBOM data can live in one document or in linked documents.
Is a QBOM only for organisations using quantum computers?
No. CERT-In's QBOM also covers quantum-safe cryptography, and in migration practice it is used to track the quantum exposure of ordinary classical cryptography. Any organisation planning a post-quantum migration benefits from one.
Sources
- Technical Guidelines on SBOM, QBOM & CBOM, AIBOM and HBOM, Version 2.0 (9 July 2025)CERT-In, Government of Indiawww.cert-in.org.in/PDF/TechnicalGuidelines-on-SBOM,QBOM&CBOM,AIBOM_and_HBOM_ver2.0.pdf
- Cryptography Bill of Materials (CBOM)OWASP CycloneDXcyclonedx.org/capabilities/cbom/
- Technical Report: Migration to Post Quantum Cryptography (TEC 910018:2025)Telecommunication Engineering Centre, DoTtec.gov.in/pdf/TR/Final%20technical%20report%20on%20migration%20to%20PQC%2028-03-25.pdf
- Implementation of Quantum Safe Ecosystem in India: Report of the Task Force (February 2026)Department of Science & Technology, Government of Indiadst.gov.in/sites/default/files/Report_TaskForce_PQMigration_4Feb26%20(v1).pdf
- RBI constitutes Expert Committee on Quantum Secure and Adaptive Financial Ecosystem (Q-SAFE) (25 May 2026)Reserve Bank of Indiarbi.org.in/Scripts/BS_PressReleaseDisplay.aspx?prid=62803
Sources checked in September 2026. Regulations and guidance change; always refer to the issuing body’s current publication. This content is for general information and is not legal advice.