%% You should probably cite draft-ietf-core-oscore-groupcomm instead of this I-D.
@techreport{tiloca-core-multicast-oscoap-00,
    number =    {draft-tiloca-core-multicast-oscoap-00},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-tiloca-core-multicast-oscoap/00/},
    author =    {Marco Tiloca and Göran Selander and Francesca Palombini},
    title =     {{Secure group communication for CoAP}},
    pagetotal = 15,
    year =      2016,
    month =     oct,
    day =       12,
    abstract =  {This document describes a method for application layer protection of messages exchanged with the Constrained Application Protocol (CoAP) in a group communication context. The proposed approach relies on Object Security of CoAP (OSCOAP) and the CBOR Object Signing and Encryption (COSE) format. All security requirements fulfilled by OSCOAP are maintained for multicast CoAP request messages and related unicast CoAP response messages. Source authentication of all messages exchanged within the group is ensured, by means of digital signatures produced through asymmetric private keys of sender devices and embedded in the protected CoAP messages.},
}