3.13.3 Encrypted Assertion

The contents of the assertion can be encrypted to protect against exposing sensitive information to untrusted third parties, such as a user agent. This protection is especially relevant when the assertion contains personal information about the subscriber.

A trust agreement MAY require the encryption of assertion contents in other situations.

While most assertion formats support encryption of the entire assertion, some assertion formats allow for only the personal information portions of the assertion to be encrypted, providing the selective disclosure of sensitive information to the RP without encrypting the entire assertion. When portions of the assertion are encrypted, only an RP that holds the necessary decryption key will be able to access the encrypted information in the assertion.

When encrypting assertions, the IdP SHALL encrypt the contents of the assertion using the RP’s encryption key with approved cryptography. For example, a SAML assertion can be encrypted using XML-Encryption, while an OpenID Connect ID Token can be encrypted using JSON Web Encryption (JWE).

When used with back-channel presentation, an assertion can also be encrypted in transit with a mutually authenticated TLS connection if there are no intermediaries between the IdP and RP that interrupt the TLS channel.

The meaning of subject identifiers is contextual to their target systems, unlike other possible identifiers, such as SSNs, email addresses, or driver’s license numbers. Therefore, subject identifiers alone do not trigger encryption requirements based on protecting personal information.

1. Overview

1.1 References

1.2 Identified Requirements

1.3 Related Regulations

2. Identified Requirements

3. Related Regulations

• NIST -

  EN: Publications of the National Institute of Standards and Technology (NIST), U.S. Department of Commerce, https://www.nist.gov/, from their electronic versions (OSCAL; SP 800-63-4 from its HTML version, https://pages.nist.gov/800-63-4/). Works of NIST employees are not subject to copyright protection in the United States (17 U.S.C. § 105); the OSCAL content is dedicated to the public domain worldwide (CC0 1.0); outside the United States NIST grants the right to reprint its technical series publications in all formats (NIST copyright statement). Republished courtesy of the National Institute of Standards and Technology; each document names its citation. Divided into sections and converted into the GRCA format, the wording unchanged. Only the versions published by NIST are authoritative.

  DE: Veröffentlichungen des National Institute of Standards and Technology (NIST), U.S. Department of Commerce, https://www.nist.gov/, aus ihren elektronischen Fassungen (OSCAL; SP 800-63-4 aus ihrer HTML-Fassung, https://pages.nist.gov/800-63-4/). Werke von NIST-Beschäftigten sind in den USA urheberrechtlich nicht geschützt (17 U.S.C. § 105); die OSCAL-Inhalte sind weltweit gemeinfrei gestellt (CC0 1.0); außerhalb der USA räumt das NIST das Recht ein, seine Technical-Series-Publikationen in allen Formaten neu zu veröffentlichen (Copyright-Hinweis des NIST). „Republished courtesy of the National Institute of Standards and Technology“; jedes Dokument nennt seine Zitierangabe. In Abschnitte aufgeteilt und in das GRCA-Format umgewandelt, der Wortlaut unverändert. Maßgeblich sind allein die vom NIST veröffentlichten Fassungen.