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Authentication and Encryption Mechanism for DHCPv6
draft-cui-dhc-dhcpv6-encryption-01

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This is an older version of an Internet-Draft whose latest revision state is "Expired".
Authors Yong Cui , Lishan Li , Jianping Wu , Yiu Lee
Last updated 2015-07-06
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draft-cui-dhc-dhcpv6-encryption-01
DHC Working Group                                                 Y. Cui
Internet-Draft                                                     L. Li
Intended status: Standards Track                                   J. Wu
Expires: January 7, 2016                             Tsinghua University
                                                                  L. Yiu
                                                                 Comcast
                                                            July 6, 2015

           Authentication and Encryption Mechanism for DHCPv6
                   draft-cui-dhc-dhcpv6-encryption-01

Abstract

   The Dynamic Host Configuration Protocol for IPv6 (DHCPv6) enables
   DHCPv6 servers to configure network parameters.  However, due to the
   unsecured nature, various critical identifiers used in DHCPv6 are
   vulnerable to several types of attacks, particularly pervasive
   monitoring.  This document provides a mechanism to secure DHCPv6
   messages, which achieves the server authentication and encryption
   based on sender's certificate/public key.

Status of This Memo

   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 http://datatracker.ietf.org/drafts/current/.

   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."

   This Internet-Draft will expire on January 7, 2016.

Copyright Notice

   Copyright (c) 2015 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
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents

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   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Requirements Language . . . . . . . . . . . . . . . . . . . .   3
   3.  Solution A: Authentication before Encrypted DHCPv6  . . . . .   4
     3.1.  Solution Overview . . . . . . . . . . . . . . . . . . . .   4
     3.2.  Client Behavior . . . . . . . . . . . . . . . . . . . . .   6
     3.3.  Server Behavior . . . . . . . . . . . . . . . . . . . . .   6
     3.4.  Possible Problem  . . . . . . . . . . . . . . . . . . . .   7
   4.  Solution B: Authentication with Encrypted DHCPv6  . . . . . .   7
     4.1.  Solution Overview . . . . . . . . . . . . . . . . . . . .   7
     4.2.  Client Behavior . . . . . . . . . . . . . . . . . . . . .   9
     4.3.  Server Behavior . . . . . . . . . . . . . . . . . . . . .   9
     4.4.  Possible Problem  . . . . . . . . . . . . . . . . . . . .  10
   5.  New DHCPv6 Messages . . . . . . . . . . . . . . . . . . . . .  10
   6.  New DHCPv6 Options  . . . . . . . . . . . . . . . . . . . . .  10
   7.  Security Considerations . . . . . . . . . . . . . . . . . . .  11
   8.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  11
   9.  Contributors  . . . . . . . . . . . . . . . . . . . . . . . .  12
   10. References  . . . . . . . . . . . . . . . . . . . . . . . . .  12
     10.1.  Normative References . . . . . . . . . . . . . . . . . .  12
     10.2.  Informative References . . . . . . . . . . . . . . . . .  13
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  13

1.  Introduction

   The Dynamic Host Configuration Protocol for IPv6 [RFC3315] enables
   DHCPv6 servers to configure network parameters dynamically.
   [I-D.ietf-dhc-dhcpv6-privacy] analyses the DHCPv6 privacy issues and
   discusses how various identifiers used in DHCPv6 could become a
   source for gleaning additional information of an individual.  Due to
   the unsecured nature of DHCPv6, the various critical identifiers are
   vulnerable to several types of attacks, particularly pervasive
   monitoring [RFC7258].

   Prior work has addressed some aspects of DHCPv6 security, but until
   now there has been little work on privacy between a DHCPv6 client and
   server.  Secure DHCPv6 [I-D.ietf-dhc-sedhcpv6] provides the
   authentication mechanism between DHCPv6 client and server along with
   the DHCPv6 transaction.  However, the DHCPv6 message is still
   transmitted in clear text and the private information within the
   DHCPv6 message is not protected from pervasive monitoring.  The IETF

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   has expressed strong agreement that PM is an attack that needs to be
   mitigated where possible.  Anonymity profile for DHCP clients
   [I-D.ietf-dhc-anonymity-profile] provides guidelines on the
   composition of DHCPv4 or DHCPv6 request to minimize the disclosure of
   identifying information.  However, anonymity profile cannot protect
   the all identifiers used in DHCP if new option containing some
   private information is defined.  In addition, the anonymity profile
   cannot work in some situation where the clients want anonymity to
   attackers but not to the valid DHCP server.

   The document discusses two possible solutions to achieve the server
   authentication and encryption between DHCPv6 client and server.  It
   should be noted that the two solutions cannot coexist at the same
   time.  One solution need to be selected to solve the DHCPv6 privacy
   problem.  Solution A specifies a security mechanism which achieve the
   server authentication before the DHCPv6 configuration process.  Two
   new DHCPv6 messages, Encryption-Request and Encryption-Reply, are
   defined to exchange the certificates, timestamps, signatures of the
   server.  After the server authentication, the following DHCPv6
   messages are encrypted and encapsulated into two newly defined DHCPv6
   messages: Encrypted-Query and Encrypted-Response.  In this way,
   identifiers including the entity's DUID are protected from pervasive
   monitoring.

   In solution B, the server authentication process is done during the
   Solicit-Advertise exchange.  The following DHCPv6 messages are
   encrypted using public keys, and are also encapsulated into
   Encrypted-Query and Encrypted-Response.  In this way, the DHCPv6
   server and client's privacy is protected.

   The proposed secure mechanism can provide the following functions to
   improve security of DHCPv6 client and server:

   o  Identify the DHCPv6 server.

   o  Encrypt the DHCPv6 configuration messages between a DHCPv6 server
      and a client once the public keys exchange is completed.

   o  Anti-replay protection based on timestamps.

2.  Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in [RFC2119].

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3.  Solution A: Authentication before Encrypted DHCPv6

3.1.  Solution Overview

   This solution proposes the client authenticates the server before
   standard DHCPv6 transactions; The server and client use public keys
   to encrypt all other DHCPv6 messages.

   In the authentication process, two new client-server DHCPv6 messages,
   Encryption-Request and Encryption-Reply, are defined for the server
   authentication.  Once the server authentication is finished, the
   following DHCPv6 transactions can be encrypted using the sender's
   public key.  The encrypted DHCPv6 messages for the following
   transactions [RFC3315] are put into the newly defined Encrypted-
   Message option, and encapsulated into Encrypted-Query and Encrypted-
   Response DHCPv6 messages that are defined in this document.  The
   Encrypted-Query message is sent from client to server, which contains
   the server identifier option and an Encrypted-Message option.  The
   Encrypted-Response message is sent from server to client, containing
   the Encrypted-Message option.

   This solution is based on the public/private key pairs of the DHCPv6
   client and server.  The server and client firstly generate a pair of
   public/private keys.  The server should acquire a public key
   certificate from the CA that signs the public key.  The deployment of
   the PKI is out of the scope of this document.  If the client does not
   have public/private key pair, cleartext is used as the baseline
   communication security policy.

   The solution adds a two-way communication before the DHCPv6
   configuration process.  The DHCPv6 client firstly multicasts an
   Encryption-Request message to the DHCPv6 servers.  The message
   contains no options, so that it reveals no private information of the
   client.  When receiving the Encryption-Request message, the server
   replies the Encryption-Reply message that contains the server's
   certificate, signature and DUID.

   Upon the receipt of the Encryption-Reply message, the DHCPv6 client
   verifies the identity of the DHCPv6 server and checks the timestamp.
   If the validation and timestamp check are successful, the client gets
   the server's DUID as well as the public key from the certificate.
   For the authenticated servers, the client selects one DHCPv6 server
   for network parameters configuration.

   After the server authentication, the following DHCPv6 messages are
   encrypted with the recipient's public key and encapsulated into the
   Encrypted-Message option.  The Solicit message MUST contain the
   public key option, the timestamp option and the signature option for

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   client's public key exchange.  The client sends the Encrypted-Query
   message to server, which carries the server identifier option and an
   Encrypted-Message option.  The server identifier option is externally
   visible.  For the authenticated target server, it decrypts the
   Encrypted-Message option by its private key.  The DHCPv6 server drops
   message containing a server identifier option not matching the
   server's DUID, thus not paying cost to decrypt the message.  The
   DHCPv6 server sends the Encrypted-Response message to client which
   contains the Encrypted-Message option.

   [RFC7283] enables relays to support the newly defined DHCPv6 messages
   without any change.

           +-------------+                           +-------------+
           |DHCPv6 Client|                           |DHCPv6 Server|
           +-------------+                           +-------------+
                  |            Encryption-Request            |
                  |----------------------------------------->|
                  |                                          |
                  |            Encryption-Reply              |
                  |<-----------------------------------------|
                  |  certificate option   signature option   |
                  |            timestamp option              |
                  |         server identifier option         |
                  |                                          |
                  |            Encryption-Query              |
                  |----------------------------------------->|
                  |    Encrypted-Message option (Solicit)    |
                  |      server identifier option            |
                  |                                          |
                  |            Encryption-Query              |
                  |<-----------------------------------------|
                  |  Encrypted-Message option (Advertise)    |
                  |                                          |
                  |            Encryption-Query              |
                  |----------------------------------------->|
                  |    Encrypted-Message option (Request)    |
                  |      server identifier option            |
                  |                                          |
                  |            Encryption-Query              |
                  |<-----------------------------------------|
                  |    Encrypted-Message option (Reply)      |

              DHCPv6 Authentication and Encryption Procedure

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3.2.  Client Behavior

   If the client supports the secure mode, it MUST generate a public/
   private key pair.  For the client supporting the secure mode, it
   multicasts the Encryption-Request to the DHCPv6 servers before
   sending SOLICIT message.  To protect the client's privacy, the
   Encryption-Request message SHOULD reveal no private information to
   the server.  To provide a "dummy" Encryption-Request message, it is
   RECOMMENDED to send the Encryption-Request message with no option.

   When the DHCPv6 client receives the Encryption-Reply message, it
   validates the server's identity according to the rule defined in
   [RFC5280] and checks the timestamp according to the rule defined in
   [I-D.ietf-dhc-sedhcpv6].  The client creates a local trusted
   certificate record for the verified certificate and the corresponding
   server identifier.  The client obtains the server's public key from
   the certificate.  For the authenticated servers, the client selects
   one DHCPv6 server for network parameters configuration.

   Once the public keys exchange is completed, the DHCPv6 messages sent
   from client to server are encrypted using the public key retrieved
   from the server's certificate.  The encrypted DHCPv6 message is
   encapsulated into the Encrypted-Message option.  The Encrypted-Query
   message is constructed with the Encrypted-Message option and server
   identifier option.  The server identifier option is externally
   visible to avoid extra cost by those unselected servers.  If the
   client fails to get the proper parameters from the chosen server, it
   will send the Encrypted-Query message to other authenticated servers
   for IPv6 configuration.  The Solicit message MUST contain the public
   key option, the timestamp option and the signature option for
   client's public key exchange.  The selected server is informed of the
   client's public key through the Solicit message which is decrypted
   from the Encrypted-Message option.

   For the received Encrypted-Response message, the client extracts the
   Encrypted-Message option and decrypts it using its private key to
   obtain the original DHCPv6 message.  Then it handles the message as
   per [RFC3315].

3.3.  Server Behavior

   When the DHCPv6 server receives the Encryption-Request message, it
   replies the Encryption-Reply message to the client, which includes
   the server's digital signature, certificate, timestamp and server
   identifier.

   On the receipt of Encrypted-Query message, the server checks the
   visible server identifier option.  It decrypts the Encrypted-Message

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   option using its private key if it is the target server.  The DHCPv6
   server drops the messages that are not for it, thus not paying cost
   to decrypt the message.  If the decrypted message is the Solicit
   message, the server checks the timestamp and the signature.  If the
   check succeeds, the server is informed of the client's public key
   through the contained public key option.

   The DHCPv6 messages, which is sent from server to client, is
   encrypted using the public key from the client's certificate.  The
   encrypted DHCPv6 message is encapsulated into the Encrypted-Message
   option.  The Encrypted-Response message contains the Encrypted-
   Message option.

3.4.  Possible Problem

   Once the authentication is completed, one DHCPv6 server is selected
   for address allocation from the authenticated DHCPv6 servers.  And
   the following DHCPv6 message is encrypted using the selected server's
   public key.  If the client fails to get the proper parameters from
   the chosen server, it will send the Encrypted-Query message to other
   authenticated server for parameters configuration until the client
   obtains the proper parameters.  It should be noted that if the client
   does not have connectivity to an authority, there might be problem
   for the client to get the certificate and validate it, which
   potentially breaks the mechanism.

4.  Solution B: Authentication with Encrypted DHCPv6

4.1.  Solution Overview

   Another solution is also provided, which does not introduce new
   messages exchange procedure.  The two solutions cannot coexist.  One
   solution could be selected to solve the DHCPv6 privacy problem.  This
   proposed solution is also based on the public/private key pairs of
   the DHCPv6 client and server.  And the server obtains a public key
   certificate from CA that signs the public key.  The deployment of the
   PKI is out of the scope of this document.

   The server authentication and public keys exchange process are
   completed along with the DHCPv6 transaction.  We recommend that the
   Solicit message is modified to carry no privacy information about the
   client, such as the client's DUID.  In Solicit message, the client
   includes its public key for encryption, while in Advertise message,
   the server would include its own certificate.

   For the encrypted message transaction, it follow the same encryption
   pattern as specified in solution A.  There are one newly DHCPv6
   option: Encrypted-Message option and two newly defined DHCPv6

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   message: Encrypted-Query and Encrypted-Response.  The Encrypted-
   Message carries the encrypted DHCPv6 message.  The Encrypted-Query
   message is sent from client to server, which contains the server
   identifier option and an Encrypted-Message option.  The Encrypted-
   Response message is sent from server to client which contains the
   Encrypted-Message option.

   The Solicit message is recommended to carry no privacy information of
   the client.  Simultaneously, the client's public key, timestamp,
   signature are included in the Solicit message.  The server
   encapsulates the encrypted Advertise message into the Encrypted-
   Message option.  The server then sends the Encrypted-Response message
   to the client with Encrypted-Message option, the certificate option,
   the signature option, the timestamp option.  The DHCPv6 client
   validates the server's identity and checks the timestamp.  If the
   validation and timestamp check are successful, the client decrypts
   the Encrypted-Message option and get the Advertise message.  For the
   following DHCPv6 transaction, the client sends the Encrypted-Query
   message to the server, which contains the server identifier option
   and Encrypted-Message option.  The server sends the Encrypted-
   Response message to the client, which contains the Encrypted-Message
   option.

            +-------------+                           +-------------+
            |DHCPv6 Client|                           |DHCPv6 Server|
            +-------------+                           +-------------+
            |             Solicit message                   |
            |---------------------------------------------->|
            |    certificate option    signature option     |
            |                                               |
            |          Encrypted-Response message           |
            |<----------------------------------------------|
            |    certificate option   signature option      |
            |          Encrypted-Message option             |
            |                                               |
            |          Encrypted-Query message              |
            |---------------------------------------------->|
            |    Server ID option  Encrypted-Message option |
            |                                               |
            |          Encrypted-Response message           |
            |<----------------------------------------------|
            |         Encrypted-Message option              |
            |                                               |

                      DHCPv6 Authentication Procedure

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4.2.  Client Behavior

   If the client supports the secure mode, it MUST generate a public/
   private key pair.  For the client supporting the secure mode, it
   generates the Solicit message that carries no privacy information
   about the client, such as client's DUID.  The client multicasts the
   Solicit message to the DHCPv6 servers, which contains the client's
   public key, timestamp and signature.  After creating the entire
   DHCPv6 header and options, the signature is created that is signed by
   the client's private key.

   When the DHCPv6 client receives the Encrypted-Response message with
   the certificate option, signature option, and timestamp option, it
   verifies the certificate according to the rule defined in [RFC5280]
   and checks the timestamps according to the rule defined in
   [I-D.ietf-dhc-sedhcpv6].  The client creates a local trust
   certificate record for the verified certificate and the corresponding
   server identifier.  Simultaneously, the client decrypts the content
   of Encrypted-Message option to obtain the Advertise message.

   Once the authentication is completed, the client sends the Encrypted-
   Query message to the server, which contains the server identifier
   option and Encrypted-Message option.  The Encrypted-Message option
   contains the DHCPv6 message encrypted with the server's public key.
   The server identifier option is externally visible to avoid extra
   decryption cost by those unchosen servers.

   When the client receives the Encrypted-Response message, the client
   decrypts the Encrypted-Message option to obtain the DHCPv6 message.
   The client follows the rules in [RFC3315] when handling the original
   DHCPv6 messages.

4.3.  Server Behavior

   When the DHCPv6 server receives a Solicit message, it checks the
   timestamp and the signature.  If the check is successful, it sends
   the Encrypted-Response message to the client, which includes the
   server's certificate, timestamp, signature and Encrypted-Message
   option containing the encrypted Advertise message.

   After the Authentication, the server sends the Encrypted-Response
   message to client, which contains the Encrypted-Message option.  For
   the received Encrypted-Query message, the server checks the server
   identifier option.  It decrypts the Encrypted-Message option using
   its private key if it is the target server.  The DHCPv6 server drops
   messages that are not targeted for it, thus not paying cost to
   decrypt the message.

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4.4.  Possible Problem

   According to [RFC3315], the client DUID is used for selecting
   addresses to assign to an IA.  Other options which carries the
   privacy information, such as IA_NA or IA_TA, may also affect the
   address selection.  In addtion, the Solicit message without client
   DUID violates Solicit message validation described in [RFC3315].

5.  New DHCPv6 Messages

   For solution A, there are four DHCPv6 message defined: Encryption-
   Request, Encryption-Reply, Encrypted-Query and Encrypted-Response.
   For sulution B, there are only two DHCPv6 message defined: Encrypted-
   Query and Encrypted-Response.  Both DHCPv6 messages defined in this
   document share the following format:

      0                   1                   2                   3
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |    msg-type   |               transaction-id                  |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                                                               |
     .                            options                            .
     .                           (variable)                          .
     |                                                               |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                Figure 1: The format of New DHCPv6 Messages

   msg-type        For solution A: Encrypted-Query (TBA1), Encrypted-
                   Response (TBA2) Encryption-Request (TBA3),
                   Encryption-Reply (TBA4).  For solution B: Encrypted-
                   Query (TBA1), Encrypted-Response (TBA2).

   transaction-id  The transaction ID for this message exchange.

   options         Options carried in this message.

6.  New DHCPv6 Options

   For the two solution, the Encrypted-Message option are all defined,
   which carries the DHCPv6 message that is encrypted with the
   recipient's public key.

   The format of the DHCPv4 Message option is:

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      0                   1                   2                   3
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |          option-code          |           option-len          |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                                                               |
     .                  encrypted DHCPv6 message                     .
     .                                                               .
     .                                                               .
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                 Figure 2: Encrypted-Message Option Format

   option-code  OPTION_Encrypted_MSG (TBA5 for solution A; TBA3 for
      solution B).

   option-len  Length of the encrypted DHCPv6 message.

   encrypted DHCPv6 message  The encrypted DHCPv6 message sent by the
      client or the server.  In a Encrypted-Query message, it contains
      encrypted DHCPv6 message sent by a client.  An Encrypted-response
      message contains encrypted DHCPv6 message sent by a server in
      response to a client.

7.  Security Considerations

   TBD

8.  IANA Considerations

   For solution A, there are four new DHCPv6 messages defined and one
   new DHCPv6 option defined.  If the solution A is selected, the IANA
   is requested to assign values for these four new messages and one new
   option.

   The four messages are:

   o  Encrypted-Query message (TBA1).

   o  Encrypted-Response message (TBA2).

   o  Encryption-Request message (TBA3).

   o  Encryption-Reply message (TBA4).

   The one option is:

   o  Encrypted-Message option (TBA5).

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   For solution B, there are two new DHCPv6 messages defined and one new
   DHCPv6 option defined.  If the solution B is selected, the IANA is
   requested to assign values for these two new messages and one new
   option.

   The four messages are:

   o  Encrypted-Query message (TBA1).

   o  Encrypted-Response message (TBA2).

   The one option is:

   o  Encrypted-Message option (TBA3).

9.  Contributors

   The authors would like to thank Bernie Volz, Ralph Droms, Yiu Lee,
   Tomek Mrugalski, Fred Baker, Qi Sun, Zilong Liu, Cong Liu.

10.  References

10.1.  Normative References

   [I-D.ietf-dhc-sedhcpv6]
              Jiang, S., Shen, S., Zhang, D., and T. Jinmei, "Secure
              DHCPv6", draft-ietf-dhc-sedhcpv6-08 (work in progress),
              June 2015.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC3315]  Droms, R., Bound, J., Volz, B., Lemon, T., Perkins, C.,
              and M. Carney, "Dynamic Host Configuration Protocol for
              IPv6 (DHCPv6)", RFC 3315, July 2003.

   [RFC5280]  Cooper, D., Santesson, S., Farrell, S., Boeyen, S.,
              Housley, R., and W. Polk, "Internet X.509 Public Key
              Infrastructure Certificate and Certificate Revocation List
              (CRL) Profile", RFC 5280, May 2008.

   [RFC7283]  Cui, Y., Sun, Q., and T. Lemon, "Handling Unknown DHCPv6
              Messages", RFC 7283, July 2014.

   [RFC7435]  Dukhovni, V., "Opportunistic Security: Some Protection
              Most of the Time", RFC 7435, December 2014.

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10.2.  Informative References

   [I-D.ietf-dhc-anonymity-profile]
              Huitema, C., Mrugalski, T., and S. Krishnan, "Anonymity
              profile for DHCP clients", draft-ietf-dhc-anonymity-
              profile-01 (work in progress), June 2015.

   [I-D.ietf-dhc-dhcpv6-privacy]
              Krishnan, S., Mrugalski, T., and S. Jiang, "Privacy
              considerations for DHCPv6", draft-ietf-dhc-
              dhcpv6-privacy-00 (work in progress), February 2015.

   [RFC7258]  Farrell, S. and H. Tschofenig, "Pervasive Monitoring Is an
              Attack", BCP 188, RFC 7258, May 2014.

Authors' Addresses

   Yong Cui
   Tsinghua University
   Beijing  100084
   P.R.China

   Phone: +86-10-6260-3059
   Email: yong@csnet1.cs.tsinghua.edu.cn

   Lishan Li
   Tsinghua University
   Beijing  100084
   P.R.China

   Phone: +86-15201441862
   Email: lilishan9248@126.com

   Jianping Wu
   Tsinghua University
   Beijing  100084
   P.R.China

   Phone: +86-10-6278-5983
   Email: jianping@cernet.edu.cn

Cui, et al.              Expires January 7, 2016               [Page 13]
Internet-Draft              DHCPv6 Encryption                  July 2015

   Yiu Lee
   Comcast
   Philadelphia  19103
   USA

   Email: yiu_lee@cable.comcast.com

Cui, et al.              Expires January 7, 2016               [Page 14]