%% You should probably cite rfc7508 instead of this I-D. @techreport{cailleux-secure-headers-02, number = {draft-cailleux-secure-headers-02}, type = {Internet-Draft}, institution = {Internet Engineering Task Force}, publisher = {Internet Engineering Task Force}, note = {Work in Progress}, url = {https://datatracker.ietf.org/doc/draft-cailleux-secure-headers/02/}, author = {Laurent Cailleux and Chris Bonatti}, title = {{Securing Header Fields with S/MIME}}, pagetotal = 20, year = 2013, month = jan, day = 10, abstract = {This document describes how the S/MIME protocol can be extended in order to secure message header fields. This technology provides security services such as data integrity, non-repudiation and confidentiality. This extension is referred to as 'Secure Headers'.}, }