| Internet-Draft | Fair Share Cost Token | April 2026 |
| Bransky & Birkholz | Expires 11 October 2026 | [Page] |
Software suppliers often use dozens, if not hundreds of open source packages in their products. To ensure that there is a well-defined supply chain, suppliers often want to create a business relationship with the creators of each of the open source packages. To enable this, the transaction cost must be very low, which may be supported using a solution based on Supply Chain Integrity, Transparency, and Trust (scitt) tokens. Specifically, Fair Share Cost Tokens (FSCT) provide some forensic readiness in case there is a dispute about whether the supplier bore their fair share of the cost of keeping the open source product safe and secure.¶
This note is to be removed before publishing as an RFC.¶
Discussion of this document takes place on the Supply Chain Integrity, Transparency, and Trust Working Group mailing list (scitt@ietf.org), which is archived at https://mailarchive.ietf.org/arch/browse/scitt/.¶
Source for this draft and an issue tracker can be found at https://github.com/cabo/fsct.¶
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/.¶
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This Internet-Draft will expire on 11 October 2026.¶
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.¶
An intro giving a very high level, informal overview of that FSCTs do. This will employ images like this one:¶
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.¶
In this document, CDDL [RFC8610] [RFC9165] [RFC9741] is used to describe the data formats.¶
The reader is assumed to be familiar with the vocabulary and concepts defined in [RFC9334].¶
This section is to be removed before publishing as an RFC.¶
RFC Editor: Please remove the entire section before publication, as well as the reference to RFC 7942.¶
This section records the status of known implementations of the protocol defined by this specification at the time of posting of this Internet-Draft, and is based on a proposal described in [RFC7942]. The description of implementations in this section is intended to assist the IETF in its decision processes in progressing drafts to RFCs. Please note that the listing of any individual implementation here does not imply endorsement by the IETF. Furthermore, no effort has been spent to verify the information presented here that was supplied by IETF contributors. This is not intended as, and must not be construed to be, a catalog of available implementations or their features. Readers are advised to note that other implementations may exist.¶
According to [RFC7942], "this will allow reviewers and working groups to assign due consideration to documents that have the benefit of running code, which may serve as evidence of valuable experimentation and feedback that have made the implemented protocols more mature. It is up to the individual working groups to use this information as they see fit".¶
Discuss.¶
The privacy considerations outlined in Section 11 of [RFC9334] are fully applicable. In particular, ...¶
The security considerations discussed in Section 12.2 of [RFC9334] concerning the protection of individual messages are fully applicable. The following subsections provide further elaboration ...¶
RFC Editor: Please replace "RFCthis" with the RFC number assigned to this document.¶
RFC Editor: This document uses the CPA (code point allocation) convention described in [I-D.bormann-cbor-draft-numbers]. For each usage of the term "CPA", please remove the prefix "CPA" from the indicated value and replace the residue with the value assigned by IANA; perform an analogous substitution for all other occurrences of the prefix "CPA" in the document. Finally, please remove this note.¶
Possible appendices with explanatory (non-normative) information, with more nice figures.¶
This section is to be removed before publishing as an RFC.¶
The list of currently open issues for this document can be found at https://github.com/cabo/fsct/issues.¶
The authors would like to thank Lots o. Names, We n. to find and Someone Else for their reviews and suggestions.¶
Carsten supplied some text and helped with the kramdown-rfc mechanics.¶