Network Working Group                                           P. Mutaf
Internet-Draft                                            March 23, 2008
Intended status: Informational
Expires: September 24, 2008


         Humanresolver: an introduction and model of operation
                     draft-mutaf-humanresolv-00.txt

Status of this Memo

   By submitting this Internet-Draft, each author represents that any
   applicable patent or other IPR claims of which he or she is aware
   have been or will be disclosed, and any of which he or she becomes
   aware will be disclosed, in accordance with Section 6 of BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF), its areas, and its working groups.  Note that
   other groups may also distribute working documents as Internet-
   Drafts.

   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."

   The list of current Internet-Drafts can be accessed at
   http://www.ietf.org/ietf/1id-abstracts.txt.

   The list of Internet-Draft Shadow Directories can be accessed at
   http://www.ietf.org/shadow.html.

   This Internet-Draft will expire on September 24, 2008.

Abstract

   This document introduces "humanresolver": a peer-to-peer contact
   manager application.













Mutaf                  Expires September 24, 2008               [Page 1]


Internet-Draft                humanresolver                   March 2008


Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . 3
   2.  Two modes of humanresolver  . . . . . . . . . . . . . . . . . . 3
     2.1.  Face-to-face mode . . . . . . . . . . . . . . . . . . . . . 3
     2.2.  Distant mode  . . . . . . . . . . . . . . . . . . . . . . . 3
   3.  Controlling the inbound path  . . . . . . . . . . . . . . . . . 4
   4.  Security considerations . . . . . . . . . . . . . . . . . . . . 4
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 5
   6.  Conclusion  . . . . . . . . . . . . . . . . . . . . . . . . . . 5
   7.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . 5
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . . . 5
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . . . 5
   Intellectual Property and Copyright Statements  . . . . . . . . . . 6





































Mutaf                  Expires September 24, 2008               [Page 2]


Internet-Draft                humanresolver                   March 2008


1.  Introduction

   "Humanresolver" is the name of a contact management application.
   Using humanresolver, users set IPsec security policies, sign
   certificates, distribute SIP URIs, or other identifiers e.g.  Mobile
   IP(v6) home addresses, DNS names etc., "under user control".  The
   main goal of humanresolver is to allow for distribution (not
   publication) of user contact information while efficiently fighting
   SPIT (SPam over IP Telephony) and help establishment of IPsec secure
   channels.  A user may want to distribute contact information on a
   forum, for example, to sell an item or ask for help, and remove the
   communication channel when done or upon arrival of SPIT.  In human
   resolution, unlike a traditional phonebook, phone numbers are not
   published.  Instead, a point-to-point secure communication channel is
   established with the target user, if (s)he accepts.  Instead of their
   phone numbers, the users can publish their to be defined
   "humanresolver URIs" on the web or on presence services.  This
   paradigm is very effective against SPIT.  Since there is a point-to-
   point channel between each user, the cancellation of one channel has
   no impact on others.  This scheme is analogous to but more secure
   than disposable e-mail addresses scheme (against SPAM) where a user
   distributes a different e-mail address to each contact and disable it
   when spam arrives.


2.  Two modes of humanresolver

2.1.  Face-to-face mode

   In this mode, two mobile phone users have face-to-face contact and
   wish to exchange their contact information.  One of the users enters
   or clicks on the published name or pseudo of the destination user
   (published on a local presence service).  The two hosts detect each
   other, perform mutual authentication using a short authentication
   string [SAS] and sign each other's certificate and possibly exchange
   a symmetric key.  No certification authority (CA) is needed for this
   mode.

   By signing each other's public key, the hosts contribute to a web of
   trust pattern that is potentially useful in the distant mode of
   humanresolver.  The face-to-face mode is an important existing model.
   Humanresolver takes this opportunity for better securing its distant
   mode.

2.2.  Distant mode

   In this mode, the target user publishes his/her human resolution URI
   on the web or a presence service in order to receive useful incoming



Mutaf                  Expires September 24, 2008               [Page 3]


Internet-Draft                humanresolver                   March 2008


   sessions.  The initiator user clicks on the puslished humanresolver
   URI and the initiator humanresolver application is launched.  A query
   is sent to the destination host which displays a message:

            (name) wants to add you to his(her) contact list.
                Accept? [YES/NO]"

   By pushing on the YES button, the target user can accept the incoming
   human resolution request.  The two phones will exchange SIP URIs,
   home addresses, IPsec policy information, etc.  Human name
   certification will be required in this mode.  Web of trust models or
   certification authorities can be used.  Or, security associations can
   be accepted at one's own risk.  Upon arrival of SPIT, the security
   association can be removed upon the target user's command.

   In this mode the target host may display the above message only if it
   receives a valid certificate.  Alternatively, the target host may
   return a CAPTCHA and only upon receipt of the correct solution to the
   CAPTCHA it can display the above message.  This would prevent an
   initiator user from continuously annoying the responder user by
   making display the above message with bogus requests.


3.  Controlling the inbound path

   In addition to controlling incoming session authorizations, the users
   can control the inbound path for communication.  Two hosts having
   exchanged home addresses through human resolution will not need SIP
   infrastructure e.g.  SIP triangle or trapezoid in order call each
   other.  Routing will be handled by Mobile IP.  The hosts may even
   avoid exchanging Mobile IP home addresses if the contact is not
   supposed to be kept permanently.  This feature can help the target
   user better preserve privacy and tranquility against some type of
   users.  The target user cannot be called regardless of location
   because the initiator is not given a home address.  (S)he can only be
   called "now", at this location, for example at the office.  Each time
   the initiator user needs to contact the target host, (s)he will need
   to visit the web page where the target humanresolver URI is published
   and make another request.


4.  Security considerations

   TBD.







Mutaf                  Expires September 24, 2008               [Page 4]


Internet-Draft                humanresolver                   March 2008


5.  IANA Considerations

   This document makes no request of IANA.

   Note to RFC Editor: this section may be removed on publication as an
   RFC.


6.  Conclusion

   This document described the basic motivations and theory of operation
   of the humanresolver contact manager.


7.  Acknowledgements

   TBD.


8.  References

   [SAS]  Vaudenay, S., "Secure Communications over Insecure Channels
          Based on Short Authenticated Strings", 2005.


Author's Address

   Pars Mutaf

   Email: pars.mutaf@gmail.com





















Mutaf                  Expires September 24, 2008               [Page 5]


Internet-Draft                humanresolver                   March 2008


Full Copyright Statement

   Copyright (C) The IETF Trust (2008).

   This document is subject to the rights, licenses and restrictions
   contained in BCP 78, and except as set forth therein, the authors
   retain all their rights.

   This document and the information contained herein are provided on an
   "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
   OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND
   THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS
   OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF
   THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
   WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.


Intellectual Property

   The IETF takes no position regarding the validity or scope of any
   Intellectual Property Rights or other rights that might be claimed to
   pertain to the implementation or use of the technology described in
   this document or the extent to which any license under such rights
   might or might not be available; nor does it represent that it has
   made any independent effort to identify any such rights.  Information
   on the procedures with respect to rights in RFC documents can be
   found in BCP 78 and BCP 79.

   Copies of IPR disclosures made to the IETF Secretariat and any
   assurances of licenses to be made available, or the result of an
   attempt made to obtain a general license or permission for the use of
   such proprietary rights by implementers or users of this
   specification can be obtained from the IETF on-line IPR repository at
   http://www.ietf.org/ipr.

   The IETF invites any interested party to bring to its attention any
   copyrights, patents or patent applications, or other proprietary
   rights that may cover technology that may be required to implement
   this standard.  Please address the information to the IETF at
   ietf-ipr@ietf.org.











Mutaf                  Expires September 24, 2008               [Page 6]