



Security Events                                             A. Deshpande
Internet-Draft                                                A. Parecki
Intended status: Standards Track                                    Okta
Expires: 7 November 2026                                      6 May 2026


Push-Based Delivery For Multiple Security Event Tokens (SET) Using HTTP
            draft-deshpande-secevent-http-multi-set-push-02

Abstract

   This specification defines how multiple Security Event Tokens (SETs)
   can be delivered to an intended recipient using HTTP POST over TLS.
   The SETs are transmitted in the body of an HTTP POST request to an
   endpoint operated by the recipient, and the recipient indicates
   successful or failed transmission via the HTTP response.

About This Document

   This note is to be removed before publishing as an RFC.

   The latest revision of this draft can be found at
   https://appsdesh.github.io/draft-deshpande-secevent-http-multi-set-
   push/draft-deshpande-secevent-http-multi-set-push.html.  Status
   information for this document may be found at
   https://datatracker.ietf.org/doc/draft-deshpande-secevent-http-multi-
   set-push/.

   Discussion of this document takes place on the Security Events
   Working Group mailing list (mailto:id-event@ietf.org), which is
   archived at https://mailarchive.ietf.org/arch/browse/id-event/.
   Subscribe at https://www.ietf.org/mailman/listinfo/id-event/.

   Source for this draft and an issue tracker can be found at
   https://github.com/appsdesh/draft-deshpande-secevent-http-multi-set-
   push.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.





Deshpande & Parecki      Expires 7 November 2026                [Page 1]

Internet-Draft               Push-multi-SET                     May 2026


   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on 7 November 2026.

Copyright Notice

   Copyright (c) 2026 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents (https://trustee.ietf.org/
   license-info) in effect on the date of publication of this document.
   Please review these documents carefully, as they describe your rights
   and restrictions with respect to this document.  Code Components
   extracted from this document must include Revised BSD License text as
   described in Section 4.e of the Trust Legal Provisions and are
   provided without warranty as described in the Revised BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Conventions and Definitions . . . . . . . . . . . . . . . . .   3
   3.  Push endpoint to receive multiple SETs  . . . . . . . . . . .   4
   4.  SET Delivery Semantics  . . . . . . . . . . . . . . . . . . .   4
     4.1.  Acknowledgement for all SETs  . . . . . . . . . . . . . .   4
     4.2.  Uniqueness of SETs  . . . . . . . . . . . . . . . . . . .   5
     4.3.  Transmitting SETs . . . . . . . . . . . . . . . . . . . .   5
       4.3.1.  The sets Field  . . . . . . . . . . . . . . . . . . .   5
     4.4.  Response Communication  . . . . . . . . . . . . . . . . .   7
       4.4.1.  Success Response  . . . . . . . . . . . . . . . . . .   7
       4.4.2.  Failure Response  . . . . . . . . . . . . . . . . . .   8
       4.4.3.  Error Response  . . . . . . . . . . . . . . . . . . .  10
   5.  Authentication and Authorization  . . . . . . . . . . . . . .  10
   6.  Delivery Reliability  . . . . . . . . . . . . . . . . . . . .  10
   7.  Security Considerations . . . . . . . . . . . . . . . . . . .  11
     7.1.  Too many SETs in the request  . . . . . . . . . . . . . .  11
     7.2.  Authentication and Authorization  . . . . . . . . . . . .  11
     7.3.  HTTP and TLS  . . . . . . . . . . . . . . . . . . . . . .  11
     7.4.  Event Delivery Latency  . . . . . . . . . . . . . . . . .  12
     7.5.  Information Disclosure in Error Responses . . . . . . . .  12
     7.6.  Event Ordering and Processing Guarantees  . . . . . . . .  12
   8.  Privacy Considerations  . . . . . . . . . . . . . . . . . . .  13
   9.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  13
   10. Normative References  . . . . . . . . . . . . . . . . . . . .  13
   Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . .  14



Deshpande & Parecki      Expires 7 November 2026                [Page 2]

Internet-Draft               Push-multi-SET                     May 2026


   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  14

1.  Introduction

   This specification defines a mechanism by which a Transmitter of a
   Security Event Token (SET) [RFC8417] can deliver multiple SETs to an
   intended SET Recipient via HTTP POST [RFC7231] over TLS in a single
   POST request.  [RFC8935] focuses on the delivery of the single SET to
   the Receiver.  When sending a large number of SETs, sending them one
   by one is inefficient.  This specification defines a way to send
   batches of SETs in a single POST request for more efficient
   transport.

   Push-Based delivery for multiple SETs is intended to help in
   following scenarios:

   *  The Transmitter of the SET has multiple outstanding SETs to be
      communicated to the Receiver

   *  The Transmitter wants to reduce the number of outbound requests to
      the same Receiver to optimize performance, avoid being ratelimited
      when number of SETs to be communicated is high

   *  The Receiver wants to optimize processing multiple SETs

   *  The Receiver wants to acknowledge or provide error responses to
      previously received SETs, but wants to do so asynchronously,
      rather than within the response to the same HTTP POST in which it
      received the SET

   This specification will handle all the use cases and scenarios for
   the [RFC8935] and make it more extensible to support multiple SETs
   per one outbound POST request.

   Similar to [RFC8935] this specification makes mechanism for
   exchanging configuration metadata such as endpoint URLs,
   cryptographic keys, and possible implementation constraints such as
   buffer size limitations between the Transmitter and Recipient is out
   of scope but is expected to be defined by profiles of this
   specification.

2.  Conventions and Definitions

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in
   BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.



Deshpande & Parecki      Expires 7 November 2026                [Page 3]

Internet-Draft               Push-multi-SET                     May 2026


3.  Push endpoint to receive multiple SETs

   Each Receiver that supports this specification MUST support a new
   push endpoint that receives multiple SETs in a single request.  This
   endpoint MUST be capable of serving HTTP POST [RFC7231] requests.
   This endpoint MUST be TLS [RFC8446] enabled and MUST reject any
   communication not using TLS.  The Transmitter obtains this endpoint
   from the Receiver is outside the scope of this specification.

4.  SET Delivery Semantics

   In this SET delivery using HTTP over TLS, a Transmitter delivers zero
   or more SETs in a JavaScript Object Notation (JSON) [RFC8259]
   document to the SET Receiver.  The Receiver either acknowledges the
   successful receipt of the SETs or indicates failure in processing of
   one or more SETs in a JSON document to the Transmitter.

   The Transmitter SHOULD periodically send a request with zero SETs to
   allow the Receiver to respond back with an ack or err for previously
   transmitted SETs that have not yet been acknowledged.

   After successful (acknowledged) SET delivery, SET Transmitters are
   not required to retain or record SETs for retransmission.  Once a SET
   is acknowledged, the SET Recipient SHALL be responsible for
   retention, if needed.  Transmitters may also discard undelivered SETs
   under deployment-specific conditions, such as if they have not been
   acknowledged (successful or failure) for over too long a period of
   time or if an excessive amount of storage is needed to retain them.
   If a Transmitter receives an acknowledgement or error for a SET it
   has no record of, the Transmitter MUST ignore that acknowledgement or
   error.

   Upon receiving a SET, the SET Recipient reads the SET and validates
   it in the manner described in Section 2 of [RFC8935].  The SET
   Recipient MUST acknowledge receipt to the SET Transmitter, and SHOULD
   do so in a timely fashion (e.g., miliseconds).  The SET Recipient
   SHALL NOT use the event acknowledgement mechanism to report event
   errors other than those relating to the parsing and validation of the
   SET.

4.1.  Acknowledgement for all SETs

   A Receiver MUST ensure that it includes the jti value of each SET it
   receives, either in an ack or a setErrs value, to the Transmitter
   from which it received the SETs.  A Transmitter SHOULD retry sending
   the same SET again if it was never responded to either in an ack
   value or in a setErrs value by a Receiver in a reasonable time
   period.  A Transmitter MAY limit the number of times it retries



Deshpande & Parecki      Expires 7 November 2026                [Page 4]

Internet-Draft               Push-multi-SET                     May 2026


   sending a SET.  A Transmitter MAY publish the retry time period and
   maximum number of retries to its peers, but such publication is
   outside the scope of this specification.

4.2.  Uniqueness of SETs

   A Transmitter MUST NOT send two SETs with the same jti value if the
   SET has been either acknowledged through ack value or produced an
   error indicated by a setErrs value.  If a Transmitter wishes to re-
   send an event after it has received a error response through a
   setErrs value, then it MUST generate a new SET that has a new (and
   unique) jti value.

4.3.  Transmitting SETs

   To transmit a SET to a SETs Recipient, the SET Transmitter makes an
   HTTP POST request to a TLS-enabled HTTP endpoint provided by the SET
   Recipient.  The body of this request is of the content type
   "application/json" and the Accept header field MUST be "application/
   json".

   A Transmitter may initiate communication with the Receiver in order
   to:

   *  Send SETs to the Receiver

   *  Receive acknowledgement of SETs in response

   It MUST contain the following fields:

4.3.1.  The sets Field

   REQUIRED.  A JSON object containing key-value pairs in which the key
   of a field is a string that contains the jti claim of the SET that is
   specified in the value of the field.  This field MAY be an empty
   object to indicate that no SETs are being delivered by the initiator
   in this communication.  The maximum number of SETs in a push MAY be
   set by the Transmitter for itself and SHOULD be communicated offline
   to the Receivers.

   The following is a non-normative example of a request.










Deshpande & Parecki      Expires 7 November 2026                [Page 5]

Internet-Draft               Push-multi-SET                     May 2026


     {
       "sets": {
         "4d3559ec67504aaba65d40b0363faad8":
         "eyJhbGciOiJub25lIn0.
         eyJqdGkiOiI0ZDM1NTllYzY3NTA0YWFiYTY1ZDQwYjAzNjNmYWFkOCIsImlhdC
         I6MTQ1ODQ5NjQwNCwiaXNzIjoiaHR0cHM6Ly9zY2ltLmV4YW1wbGUuY29tIiwi
         YXVkIjpbImh0dHBzOi8vc2NpbS5leGFtcGxlLmNvbS9GZWVkcy85OGQ1MjQ2MW
         ZhNWJiYzg3OTU5M2I3NzU0IiwiaHR0cHM6Ly9zY2ltLmV4YW1wbGUuY29tL0Zl
         ZWRzLzVkNzYwNDUxNmIxZDA4NjQxZDc2NzZlZTciXSwiZXZlbnRzIjp7InVybj
         ppZXRmOnBhcmFtczpzY2ltOmV2ZW50OmNyZWF0ZSI6eyJyZWYiOiJodHRwczov
         L3NjaW0uZXhhbXBsZS5jb20vVXNlcnMvNDRmNjE0MmRmOTZiZDZhYjYxZTc1Mj
         FkOSIsImF0dHJpYnV0ZXMiOlsiaWQiLCJuYW1lIiwidXNlck5hbWUiLCJwYXNz
         d29yZCIsImVtYWlscyJdfX19.",
         "3d0c3cf797584bd193bd0fb1bd4e7d30":
         "eyJhbGciOiJub25lIn0.
         eyJqdGkiOiIzZDBjM2NmNzk3NTg0YmQxOTNiZDBmYjFiZDRlN2QzMCIsImlhdC
         I6MTQ1ODQ5NjAyNSwiaXNzIjoiaHR0cHM6Ly9zY2ltLmV4YW1wbGUuY29tIiwi
         YXVkIjpbImh0dHBzOi8vamh1Yi5leGFtcGxlLmNvbS9GZWVkcy85OGQ1MjQ2MW
         ZhNWJiYzg3OTU5M2I3NzU0IiwiaHR0cHM6Ly9qaHViLmV4YW1wbGUuY29tL0Zl
         ZWRzLzVkNzYwNDUxNmIxZDA4NjQxZDc2NzZlZTciXSwic3ViIjoiaHR0cHM6Ly
         9zY2ltLmV4YW1wbGUuY29tL1VzZXJzLzQ0ZjYxNDJkZjk2YmQ2YWI2MWU3NTIx
         ZDkiLCJldmVudHMiOnsidXJuOmlldGY6cGFyYW1zOnNjaW06ZXZlbnQ6cGFzc3
         dvcmRSZXNldCI6eyJpZCI6IjQ0ZjYxNDJkZjk2YmQ2YWI2MWU3NTIxZDkifSwi
         aHR0cHM6Ly9leGFtcGxlLmNvbS9zY2ltL2V2ZW50L3Bhc3N3b3JkUmVzZXRFeH
         QiOnsicmVzZXRBdHRlbXB0cyI6NX19fQ."
       }
     }

   _Figure 1: Example of SET Transmission_

   In the above example, the Transmitter is sending 2 SETs to the
   Receiver.

     {
       "sets": {},
     }

   _Figure 2: Example of empty SET transmission_

   In the above example, the Transmitter is sending zero SETs to the
   Receiver.  This placeholder/empty request provides the Receiver to
   respond back with ack/err for previously transmitted SETs.

   The SET Transmitter MAY include in the request an Accept-Language
   header field to indicate to the SET Recipient the preferred
   language(s) in which to receive error message descriptions.





Deshpande & Parecki      Expires 7 November 2026                [Page 6]

Internet-Draft               Push-multi-SET                     May 2026


4.4.  Response Communication

   A Receiver MUST repond to the communication by sending an HTTP
   response.  The body of this response is of the content type
   "application/json".  It contains the following fields:

   ack REQUIRED.  An array of strings, in which each string is the jti
   value of a previously received SET that is acknowledged in this
   object.  This array MAY be empty to indicate that no previously
   received SETs are being acknowledged in this communication.

   setErrs OPTIONAL.  A JSON object containing key-value pairs in which
   the key of a field is a string that contains the jti value of a
   previously received SET that the sender of the communication object
   was unable to process.  The value of the field is a JSON object that
   has the following fields:

   err REQUIRED.  The short reason why the specified SET failed to be
   processed.  Error codes are described in Section 2.4 of [RFC8935].

   description OPTIONAL.  An explanation of why the SET failed to be
   processed

   If the response contains a description, then the response MUST
   include a Content-Language header field whose value indicates the
   language of the error descriptions included in the response body.  If
   the SET Recipient can provide error descriptions in multiple
   languages, they SHOULD choose the language to use according to the
   value of the Accept-Language header field sent by the SET Transmitter
   in the transmission request, as described in Section 5.3.5 of
   [RFC7231].  If the SET Transmitter did not send an Accept-Language
   header field, or if the SET Recipient does not support any of the
   languages included in the header field, the SET Recipient MUST
   respond with messages that are understandable by an English-speaking
   person, as described in Section 4.5 of [RFC2277].

4.4.1.  Success Response

   If the Receiver is successful in processing the request, it MUST
   return the HTTP status code 202 (Accepted).  The response MUST have
   the content-type "application/json".










Deshpande & Parecki      Expires 7 November 2026                [Page 7]

Internet-Draft               Push-multi-SET                     May 2026


     HTTP/1.1 202 Accepted
     Content-type: application/json

     {
       "ack": [
         "3d0c3cf797584bd193bd0fb1bd4e7d30"
       ]
     }

   _Figure 3: Example of SET Transmission response with ack_

   In the above example, the Receiver acknowledges one of the SETs it
   previously received.  There are no errors reported by the Receiver.

     HTTP/1.1 202 Accepted
     Content-type: application/json

     {
        "ack": [
         "f52901c499611ef94540242ac12000322",
         "0636e274399711ef9454-0242ac120002",
         "d563c72479a04ff0ba415657fa5e2cb11"
        ],
        "setErrs": {
         "4d3559ec67504aaba65d40b0363faad8" : {
           "err": "invalid_key",
           "description": "Failed validation"
         }
        }
     }

   _Figure 4: Example of SET Transmission response, ack and errors_

   In the above example, the Receiver acknowledges three of the SETs it
   previously received.  There are errors reported by the Receiver for
   acklowledging one SET.

4.4.2.  Failure Response

   In the event of a general HTTP error condition, the SET Recipient
   responds with the applicable HTTP Status Code, as defined in
   Section 6 of [RFC7231].









Deshpande & Parecki      Expires 7 November 2026                [Page 8]

Internet-Draft               Push-multi-SET                     May 2026


   When the SET Recipient detects an error parsing, or authenticating a
   SET transmitted in a SET Transmission Request, the SET Recipient
   SHALL respond with an HTTP Response Status Code of 400 (Bad Request).
   The Content-Type header field of this response MUST be "application/
   json", and the body MUST be a UTF-8 encoded JSON [RFC8259] object
   containing the following name/value pairs:

   err REQUIRED.  The short reason why the API failed to process the
   request.  (Not specific to any SETs, but usually indicate service
   level failure or processing error)

   description OPTIONAL.  A UTF-8 string containing a human-readable
   description of the error that may provide additional diagnostic
   information.  The exact content of this field is implementation
   specific.

   Note that failure responses in this specification are not specific to
   any failures related to any specific SET processing.  SET specific
   errors should be communicated by a success response payload defined
   in the Section 4.4.1 Section.

   Example error codes that can indicate API level failures MAY include
   but not limited to:

   *  invalid_request (request is malformed)

   *  authentication_failed (authentication token provided by the
      Transmitter is expired, revoked or invalid)

   *  access_denied (The Transmitter does not have adequate permissions
      to invoke this API).

   *  too_many_sets (Transmitter included too many SETs in a single
      request, this is an indication for the Transmitter to make a
      request with lower number of SETs or to comply with max SETs count
      that Receiver published outside of this spec)

      HTTP/1.1 400 Bad Request
      Content-Language: en-US
      Content-Type: application/json

      {
        "err": "authentication_failed",
        "description": "Access token has expired."
      }

   _Figure 5: Example Error Response (authentication_failed)




Deshpande & Parecki      Expires 7 November 2026                [Page 9]

Internet-Draft               Push-multi-SET                     May 2026


   Above non-normative example error response indicating that the access
   token included in the request is expired.

4.4.2.1.  Out of order delivery

   A Response may contain jti values in its ack or setErrs that do not
   correspond to the SETs received in the same Request to which the
   Response is being sent.  They MAY consist of values received in
   previous Requests.

4.4.3.  Error Response

   The Receiver MUST respond with an error response if it is unable to
   process the request.  The error response MUST include the appropriate
   error code as described in Section 2.4 of [RFC8935].

5.  Authentication and Authorization

   The Transmitter MUST verify the identity of the Receiver by
   validating the TLS certificate presented by the Receiver during the
   TLS handshake, and verifying that it is the intended recipient of the
   request, before sending the SETs.

   How the Transmitter and Receiver agree on authorization of the
   request is out of scope of this document.

   This section describes server-side authentication of the Receiver by
   the Transmitter.  Authentication of the Transmitter by the Receiver
   (e.g., via OAuth tokens, mutual TLS, or other mechanisms) is out of
   scope of this document and is expected to be defined by profiles of
   this specification.

6.  Delivery Reliability

   A Transmitter MUST attempt to deliver any SETs it has previously
   attempted to deliver to a Receiver until:

   *  It receives an acknowledgement through the ack value for that SET
      in a subsequent communication with the Receiver

   *  It receives a setErrs object for that SET in a subsequent
      communication with the Receiver









Deshpande & Parecki      Expires 7 November 2026               [Page 10]

Internet-Draft               Push-multi-SET                     May 2026


   *  It has attempted to deliver the SET a maximum number of times and
      has failed to communicate either due to communication errors or
      lack of inclusion in ack or setErrs in subsequent communications
      that were conducted for the maximum number of times.  The maximum
      number of attempts MAY be set by the Transmitter for itself and
      SHOULD be communicated offline to the Receivers

   Additionally consider Delivery Reliability aspects discussed in
   Section 4 of [RFC8935].

7.  Security Considerations

   The Security Considerations of [RFC8935], [RFC8446], and Section 17
   of [RFC9110] apply to this specification.

7.1.  Too many SETs in the request

   This mechanism allows a Transmitter to send a large number of SETs in
   a single request.  A malicious or misconfigured Transmitter could
   send an extremely large payload, attempting to exhaust memory or CPU
   resources on the Receiver during JSON parsing or SET validation.

   Receivers MUST protect themselves against such attacks.  It is
   RECOMMENDED that Receivers establish and document a reasonable upper
   limit on the number of SETs they will process in a single request.
   Transmitter MUST obey the maximum number of SETs to be communicated
   to the Receiver.  This will avoid any potential truncations/loss of
   information at the Receiver.

   If a Receiver receives a batch exceeding this limit, it SHOULD reject
   the entire request with a 413 Payload Too Large HTTP status code.

   How the Receiver conveys this upper limit to Transmitters is outside
   the scope of this specification (see Section 4.3.1 for the sets field
   definition).

7.2.  Authentication and Authorization

   Transmitter MUST follow the procedures described in section Section 5
   in order to securely authenticate and authorize Receiver

7.3.  HTTP and TLS

   Transmitter MUST use TLS [RFC8446] to communicate with Receiver and
   is subject to the security considerations of HTTP Section 17 of
   [RFC9110].





Deshpande & Parecki      Expires 7 November 2026               [Page 11]

Internet-Draft               Push-multi-SET                     May 2026


   Failure to properly validate the Receiver's TLS certificate could
   allow a Transmitter to send SETs to an impersonating endpoint,
   resulting in the disclosure of sensitive security event information
   to an unauthorized party.

7.4.  Event Delivery Latency

   The primary purpose of security event tokens is the timely
   communication of security-sensitive information.  While this
   specification enables batching for efficiency, Transmitters MUST NOT
   unduly delay the transmission of events in an attempt to create
   larger batches.

   Delaying the transmission of a time-sensitive event, such as a
   credential compromise or session revocation, defeats the purpose of
   the protocol and provides an adversary with a larger window of
   opportunity to act.

   It is RECOMMENDED that Transmitters implement a batching policy that
   sends a pending batch of SETs when either of the following conditions
   is met:

   *  The number of SETs in the batch reaches a configured size limit.

   *  A configured amount of time (e.g., 1-2 seconds) has elapsed since
      the oldest SET in the batch was generated.

   This ensures a balance between network efficiency and the real-time
   nature of the communication.

7.5.  Information Disclosure in Error Responses

   The setErrs is designed for debugging and provides valuable feedback.
   However, if implemented incorrectly, it can become a souce of
   information leakage, disclosing internal details or enable
   enumeration type attacks.

   It is RECOMMENDED that setErrs information be designed to be helpful
   without revealing sensitive information about internal architecture.

7.6.  Event Ordering and Processing Guarantees

   This specification is a transport efficiency mechanism and it does
   not address transactional aspects of the request.  Every SET is an
   independent event in the request to the Receiver.  The event ordering
   in the request does not imply any chronological dependence.  For
   chronological dependence the Receiver should look at the time related
   event claims.



Deshpande & Parecki      Expires 7 November 2026               [Page 12]

Internet-Draft               Push-multi-SET                     May 2026


   A Transmitter should not assume the ordered processing of the SETs by
   the Receiver sub-systems.  This specification does not add any
   transactional requirements on the Receiver.

   Additional security consideration in Section 5 of [RFC8935].

8.  Privacy Considerations

   Privacy Considerations from Section 6 of [RFC8935] apply.

9.  IANA Considerations

   This document has no IANA actions.

10.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/rfc/rfc2119>.

   [RFC2277]  Alvestrand, H., "IETF Policy on Character Sets and
              Languages", BCP 18, RFC 2277, DOI 10.17487/RFC2277,
              January 1998, <https://www.rfc-editor.org/rfc/rfc2277>.

   [RFC7231]  Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
              Protocol (HTTP/1.1): Semantics and Content", RFC 7231,
              DOI 10.17487/RFC7231, June 2014,
              <https://www.rfc-editor.org/rfc/rfc7231>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/rfc/rfc8174>.

   [RFC8259]  Bray, T., Ed., "The JavaScript Object Notation (JSON) Data
              Interchange Format", STD 90, RFC 8259,
              DOI 10.17487/RFC8259, December 2017,
              <https://www.rfc-editor.org/rfc/rfc8259>.

   [RFC8417]  Hunt, P., Ed., Jones, M., Denniss, W., and M. Ansari,
              "Security Event Token (SET)", RFC 8417,
              DOI 10.17487/RFC8417, July 2018,
              <https://www.rfc-editor.org/rfc/rfc8417>.

   [RFC8446]  Rescorla, E., "The Transport Layer Security (TLS) Protocol
              Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
              <https://www.rfc-editor.org/rfc/rfc8446>.




Deshpande & Parecki      Expires 7 November 2026               [Page 13]

Internet-Draft               Push-multi-SET                     May 2026


   [RFC8935]  Backman, A., Ed., Jones, M., Ed., Scurtescu, M., Ansari,
              M., and A. Nadalin, "Push-Based Security Event Token (SET)
              Delivery Using HTTP", RFC 8935, DOI 10.17487/RFC8935,
              November 2020, <https://www.rfc-editor.org/rfc/rfc8935>.

   [RFC9110]  Fielding, R., Ed., Nottingham, M., Ed., and J. Reschke,
              Ed., "HTTP Semantics", STD 97, RFC 9110,
              DOI 10.17487/RFC9110, June 2022,
              <https://www.rfc-editor.org/rfc/rfc9110>.

   [RFC9728]  Jones, M.B., Hunt, P., and A. Parecki, "OAuth 2.0
              Protected Resource Metadata", RFC 9728,
              DOI 10.17487/RFC9728, April 2025,
              <https://www.rfc-editor.org/rfc/rfc9728>.

Acknowledgments

   The authors would like to acknowledge the following individuals who
   contributed ideas, feedback, and wording that shaped and formed the
   final specification:

   Atul Tulshibagwale, Yair Sarig, Yaron Sheffer.

Authors' Addresses

   Apoorva Deshpande
   Okta
   Email: apoorva.deshpande@okta.com


   Aaron Parecki
   Okta
   Email: aaron@parecki.com


















Deshpande & Parecki      Expires 7 November 2026               [Page 14]
