Reviewer: Takeshi Takahashi Review result: Ready I do not have any particular concerns on the Security Considerations section. As mentioned in the section, the proposed extension will not pose any particular threats to the base specification. Having said that, I have minor comments and clarification questions as an individual who has read this document without prior knowledge of this topic. 1. In the abstract, The sentence "from ATIS .... Joint Task Force" will not be neceaary. For those who are familiar with SHAKEN specification, this sentence is obvious. For those who are not familiar with SHAKEN, this sentence will not provide any information that may facilitate the understanding of the overview of the draft. In either cases, the sentence will not be necessary. "to include information defined as part of ..." had better be refined further. I believe the readers wish to know the details (incl., types) of the information instead of where the specification was once defined. 2. In the abstract and/or introduction, STIR should be spelled out. I guess it is Secure Telephony Identity Revisited. 3. Terminology I feel that you use the terms "claims" and "indicators" for pointing to the same objects. If that's the case, I hope you could choose to use only one of them. Example of the use of two terminologies. 1. In the introduction, you have the sentence "This document specifies these indicators...". 2. In the introduction, you have the sentence "there are two additional claims..." 3. The title of section 4 is "Passport attest claim". and so on. 4. In section 5 "PASSporT origid claim", There is a sentence "There will likely be best practices documents that more precisely guide it's usage in real deployments". If you have such a document (including work-in-progress drafts), having a reference to this sentence will be appreciated. If there is no reference, I do not think we need this sentence here. 5. orig and origid claims If I understood correctly, both orig and origid represent identifies the same objects (including service provider-initiated calls, customers, classes of devices, etc.) In this case, if the object identified by orig and the one identified by origid is not the same, how should the receiver interpret these claims? 6. section 7 I am a bit confused. If the use of "attest" and "origid" is already defined elsewhere, what does this document define? Is the document define the use of those claims for some other protols (other than SIP)? 7. security consideration. As mentioned in this section, the values of the new "attest" and "origid" claims added by this extension are not used in the current validation step. Then, do you think we should encourage people to have another step that validates those claims added by this extension? I would appreciate your answers on these issues.
