Cryptography usage guidelines in Web standard

Veronica Cristiano - Invited Expert

Kobe, Japan & online�10–14 November 2025

Agenda

• Introductions

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• Why this breakout session

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• Why this document

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• In-depth analysis of the document

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• Open points

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Introductions

My name: Veronica

My pronouns: she/her

Who I work for: Telsy (Italy)

Why I’m here: to present “Cryptography usage in Web standards” (https://w3c.github.io/security-guidelines-cryptography/) and to collect feedback

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Why this breakout session?

• Inform you about the document

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• Align on the structure

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• Collect feedback

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• Discuss open points

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Why this document?

Context: Several Web standard use cryptographic primitives to ensure security.

Cryptography used in Web standards should be standard cryptography.

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Incorrect choices can lead to vulnerabilities or interoperability issues.

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Objective: Provide a reference (specific algorithms, parameter choices, and common pitfalls to avoid) for standardized cryptographic algorithms and their recommended use in different contexts.

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Target audience:

• web specification/application developers who do not have expertise in cryptography
• people doing security reviews on specifications

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Which one of the many algorithms should I use?

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Which primitive do I need in order to obtain a specific property?

What is the correct parameterization?

Table of content

General part

Technical part

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In-depth analysis of the document

https://w3c.github.io/security-guidelines-cryptography/

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Open points

• Any other cryptographic primitives?

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• Difference between data authenticity and authentication: consensus on notations?

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• There exist standards de jure and standards de facto (e.g., X25519 is standard de facto, not de jure). Do we want to distinguish them?

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Feedbacks/PRs are welcome! :)

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Thank you

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veronica.cristiano93@gmail.com