Cryptographic Inventory for Web Teams: Find More Than HTTPS

01 / Field notes

Executive Summary

A web team's cryptography is spread across more than its HTTPS certificate. It may sign session-related tokens, verify webhooks, protect backup keys, validate software releases and rely on third-party identity services. A migration plan that lists only the public TLS endpoint leaves important dependencies undiscovered.

NIST NCCoE's post-quantum migration work includes cryptographic discovery, while NIST's updated crypto-agility paper discusses changing cryptographic mechanisms while preserving operations. [1][2] For a small web team, the practical starting point is one application and a map of its security-relevant workflows.

The inventory below is an original working format. It is not a request to export private keys or scan infrastructure outside your authority.

02 / Field notes

Prerequisites / Lab Setup

Select a bounded application and gather its architecture diagram, dependency manifest, deployment configuration and managed-service documentation. Invite the people responsible for hosting, identity, backups and releases. Source-code access alone will not reveal every provider-controlled dependency.

Use a private worksheet. Record key identifiers and secret-store references, never the secret values. Where an algorithm or implementation is unknown, label it unknown and assign an owner to investigate. Guessing a familiar algorithm makes the inventory look complete while making later decisions less reliable.

03 / Field notes

Technical Analysis

Start from workflows and security purposes

Ask what must remain confidential, what must be authenticated and what must remain verifiable over time. Then locate the mechanism responsible. A signed webhook, for example, may use a symmetric message-authentication mechanism rather than a public-key signature. Identify the actual scheme before classifying its migration needs.

The same algorithm name can appear in different roles with different timelines. A short-lived connection and a firmware signature verified for years are not interchangeable inventory rows. Include data lifetime and verifier lifetime so the migration plan can distinguish them.

Combine evidence sources

Source review can find explicit library calls and configuration. Dependency analysis can reveal indirect use. Runtime or provider observations can show negotiated protocols. Supplier documentation can describe managed components you cannot inspect. Each evidence source has blind spots; record which one supports each row.

In a fictional blog platform, the application code contains no TLS implementation because the hosting edge handles it. The database backup tool uses a separate key-management process, and an email provider signs webhooks. A source-only search would miss much of the actual trust chain.

Do not run intrusive discovery against production simply to fill a field. Use supported read-only tools, staging observations and provider information first. Any deeper testing should have an authorized scope and an operational reason.

Add a change path, not just an algorithm name

For each dependency, identify who can change it and what would break. Can a library be upgraded? Must a supplier add support? Are older clients or devices unable to accept a new format? Is a trust anchor fixed in hardware? These constraints turn the inventory into a migration tool.

Record a planned validation method and rollback limit. A change to a token-signing algorithm may require every verifier to understand it before issuers switch. Rolling back one service while another has already changed can create an interoperability failure. Capture the dependency order instead of treating every row as an independent upgrade.

Keep the inventory alive through releases

A spreadsheet created once will drift as libraries, providers and integrations change. Attach updates to existing release and procurement workflows. A new identity provider or signing service should trigger a new inventory entry. A retired integration should be marked retired rather than silently deleted from historical records.

The forward-looking benefit is faster response to any cryptographic change, not only quantum risk. A well-owned inventory helps with algorithm deprecation, implementation defects and supplier transitions. That is a practical reason to start even when a complete post-quantum rollout depends on vendors.

04 / Field notes

Mitigation / Defense

Continue to crypto-agility procurement questions to turn gaps into supplier requirements. Use data-lifetime prioritization to decide which confidentiality dependencies need earlier attention.

05 / Field notes

References

Sources checked 28 October 2026. The crypto-agility reference is CSWP 39upd1, updated in June 2026. The blog platform is fictional, and the worksheet is not a claim of exhaustive discovery or a formal NIST assessment.

1. Migration to post-quantum cryptography ↗NIST NCCoE · accessed 2026-10-28
2. CSWP 39upd1: considerations for achieving crypto agility ↗NIST · accessed 2026-10-28

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