Internet Engineering Task Force (IETF) C. Dearlove

Internet Engineering Task Force (IETF) C. Dearlove
Request for Comments: 7859 BAE Systems
Category: Experimental May 2016
ISSN: 2070-1721

Identity-Based Signatures for
Mobile Ad Hoc Network (MANET) Routing Protocols

Abstract

This document extends RFC 7182, which specifies a framework for (and
specific examples of) Integrity Check Values (ICVs) for packets and
messages using the generalized packet/message format specified in RFC
5444. It does so by defining an additional cryptographic function
that allows the creation of an ICV that is an Identity-Based
Signature (IBS), defined according to the Elliptic Curve-Based
Certificateless Signatures for Identity-Based Encryption (ECCSI)
algorithm specified in RFC 6507.

Status of This Memo

This document is not an Internet Standards Track specification; it is
published for examination, experimental implementation, and
evaluation.

This document defines an Experimental Protocol for the Internet
community. This document is a product of the Internet Engineering
Task Force (IETF). It represents the consensus of the IETF
community. It has received public review and has been approved for
publication by the Internet Engineering Steering Group (IESG). Not
all documents approved by the IESG are a candidate for any level of
Internet Standard; see Section 2 of RFC 5741.

Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc7859.

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Copyright Notice

Copyright (c) 2016 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
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 . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5
3. Applicability Statement . . . . . . . . . . . . . . . . . . . 5
4. Specification . . . . . . . . . . . . . . . . . . . . . . . . 5
4.1. Cryptographic Function . . . . . . . . . . . . . . . . . 5
4.2. ECCSI Parameters . . . . . . . . . . . . . . . . . . . . 6
4.3. Identity . . . . . . . . . . . . . . . . . . . . . . . . 7
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8
6. Security Considerations . . . . . . . . . . . . . . . . . . . 8
6.1. Experimental Status . . . . . . . . . . . . . . . . . . . 9
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 9
7.1. Normative References . . . . . . . . . . . . . . . . . . 9
7.2. Informative References . . . . . . . . . . . . . . . . . 10
Appendix A. Example . . . . . . . . . . . . . . . . . . . . . . 12
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 17
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 17

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1. Introduction

[RFC7182] defines Integrity Check Value (ICV) TLVs for use in packets
and messages that use the generalized MANET packet/message format
defined in [RFC5444]. This specification extends the TLV definitions
therein by defining two new cryptographic function code points from
within the registries set up by [RFC7182]. This allows the use of an
Identity-Based Signature (IBS) as an ICV. An IBS has an additional
property that is not shared by all of the previously specified ICVs;
it not only indicates that the protected packet or message is valid,
but also verifies the originator of the packet/message.

This specification assumes that each router (i.e., each originator of
[RFC5444] format packets/messages) has an identity that may be tied
to the packet or message. The router may have more than one identity
but will only use one for each ICV TLV. The cryptographic strength
of the IBS is not dependent on the choice of identity.

Two options for the choice of identity are supported (as reflected by
the two code points allocated). In the first option, the identity
can be any octet sequence (up to 255 octets) included in the ICV TLV.
In the second option, the octet sequence is preceded by an address,
either the IP source address for a Packet TLV or the message
originator address for a Message TLV or an Address Block TLV. In
particular, the second option allows just the address to be used as
an identity.

Identity-based signatures allow identification of the originator of
information in a packet or message. They thus allow additional
security functions, such as revocation of an identity. (A router
could also then remove all information recorded as from that revoked
originator; the Optimized Link State Routing Protocol Version 2
(OLSRv2) [RFC7181], an expected user of this specification, can do
this.) When applied to messages (rather than packets), this can
significantly reduce the damage that a compromised router can inflict
on the network.

Identity-based signatures are based on forms of asymmetric (public
key) cryptography - Identity-Based Encryption (IBE). Compared to
symmetric cryptographic methods (such as HMAC and AES), IBE and IBS
methods avoid requiring a shared secret key that results in a single
point of failure vulnerability. Compared to more widely used
asymmetric (public key) cryptographic methods (such as RSA and
ECDSA), IBE and IBS methods have a major advantage and a major
disadvantage.

The advantage referred to is that each router can be configured once
(for its key lifetime) by a trusted authority, independently of all

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other routers. Thus, a router can connect to the authority
(typically in a secure environment) to receive a private key or can
have a private key delivered securely (out of band) from the
authority. During normal operation of the MANET, there is no need
for the trusted authority to be connected to the MANET or even to
still exist. Additional routers can be authorized with no reference
to previously authorized routers (the trusted authority must still
exist in this case). A router's public key is its identity, which
when tied to a packet or message (as is the case when using an
address as, or as part of, the identity) means that there is no need
for public key certificates or a certificate authority, and a router
need not retain key material for any other routers.

The disadvantage referred to is that the trusted authority has
complete authority, even more so than a conventional certificate
authority. Routers cannot generate their own private keys, only the
trusted authority can do that. Through the master secret held by the
trusted authority, it could impersonate any router (existing or not).
When used for IBE (not part of this specification), the trusted
authority can decrypt anything. However, note that the shared secret
key options described in [RFC7182] also have this limitation.

There are alternative mathematical realizations of identity-based
signatures. This specification uses one that has been previously
published as [RFC6507], known as Elliptic Curve-Based Certificateless
Signatures for Identity-Based Encryption (ECCSI). Similar to other
IBE/IBS approaches, it is based on the use of elliptic curves.
Unlike some, it does not use "pairings" (bilinear maps from a product
of two elliptic curve groups to another group). It thus may be
easier to implement and more efficient than some alternatives,
although with a greater signature size than some. This specification
allows the use of any elliptic curve that may be used by [RFC6507].

The computational load imposed by ECCSI (and, perhaps more so by
other IBS methods) is not trivial, though it depends significantly on
the quality of implementation of the required elliptic curve and
other mathematical functions. For a security level of 128 bits, the
ICV data length is 129 octets, which is longer than for alternative
ICVs specified in [RFC7182] (e.g., 32 octets for the similar strength
HMAC-SHA-256). The signature format used could have been slightly
shortened (to 97 octets) by using a compressed representation of an
elliptic curve point, however, at the expense of some additional work
when verifying a signature and loss of direct compatibility with
[RFC6507], and implementations thereof.

The trusted authority is referred to in [RFC6507] as the Key
Management Service (KMS). That term will be used in the rest of this
specification.

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2. Terminology

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

Additionally, this document uses the terminology of [RFC5444],
[RFC6507], and [RFC7182].

3. Applicability Statement

This specification adds an additional option to the framework
specified in [RFC7182] for use by packets and messages formatted as
described in [RFC5444]. It is applicable as described in [RFC7182]
and is subject to the additional comments in Section 6, particularly
regarding the role of the trusted authority (KMS).

Specific examples of protocols for which this specification is
suitable are Neighborhood Discovery Protocol (NHDP) [RFC6130] and
OLSRv2 [RFC7181].

4. Specification

4.1. Cryptographic Function

This specification defines a cryptographic function named ECCSI that
is implemented as specified as the "sign" function in Section 5.2.1
of [RFC6507]. To use that specification:

o The ICV is not calculated as cryptographic-function(hash-
function(content)) as defined in [RFC7182] but (like the HMAC ICVs
defined in [RFC7182]) uses the hash function within the
cryptographic function. The option "none" is not permitted for
hash-function, and the hash function must have a known fixed
length of N octets (as specified in Section 4.2).

o M, used in [RFC6507], is "content" as specified in [RFC7182].

o ID, used in [RFC6507], is as specified in Section 4.3.

o Key Management Service Public Authentication Key (KPAK), Secret
Signing Key (SSK), and Public Validation Token (PVT), which are
provided by the KMS, are as specified in Sections 4.2 and 5.1.1 of
[RFC6507].

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The length of the signature is 4N+1 octets (as specified in
[RFC6507]) whose affine coordinate format (including an octet valued
0x04 to identify this) is used unchanged.

Verification of the ICV is not implemented by the receiver
recalculating the ICV and comparing with the received ICV, as it is
necessarily incapable of doing so. Instead, the receiver evaluates
the "verify" function described in Section 5.2.2 of [RFC6507], which
may pass or fail.

To use that function M, KPAK, SSK, and PVT are as specified above,
while the Identifier (ID) is deduced from the received packet or
message (as specified in Section 4.3) using the <key-id> element in
the <ICV-value>. This element need not match that used by the
receiver, and thus when using this cryptographic function, multiple
ICV TLVs differing only in their <key-id> or in the choice of
cryptographic function from the two defined in this specification
SHOULD NOT be used unless routers are administratively configured to
recognize which to verify.

Routers MAY be administratively configured to reject an ICV TLV using
ECCSI based on part or all of <key-id>: for example, if this encodes
a time after which this identity is no longer valid (as described in
Section 4.3).

4.2. ECCSI Parameters

Section 4.1 of [RFC6507] specifies parameters n, N, p, E, B, G, and
q. The first of these, n, is specified as "A security parameter; the
size in bits of the prime p over which elliptic curve cryptography is
to be performed." For typical security levels (e.g., 128, 192, and
256 bits), n must be at least twice the required bits of security;
see Section 5.6.1 of [NIST-SP-800-57].

Selection of an elliptic curve, and all related parameters, MUST be
made by administrative means, and known to all routers. Following
[RFC6507], it is RECOMMENDED that the curves and base points defined
in Appendix D.1.2 of [NIST-FIPS-186-4] be used (note that n in that
document is q in [RFC6507]). However, an alternative curve MAY be
used.

The parameter that is required by this specification is N, which is
defined as Ceiling(n/8). The hash function used must create an
output of size N octets. For example, for 128 bit security, with n =
256 and N = 32, the RECOMMENDED hash function is SHA-256. The
signature (i.e., <ICV-data>) length is 4N+1 octets, i.e., 129 octets
for N = 32.

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Note that [RFC6507] actually refers to the predecessor to
[NIST-FIPS-186-4], but the latest version is specified here; there
are no significant differences in this regard.

4.3. Identity

There are two options for ID as used by [RFC6507], which are
indicated by there being two code points allocated for this
cryptographic function, see Section 5.

o For the cryptographic function ECCSI, ID is the element <key-id>
defined in Section 12.1 of [RFC7182]. This MUST NOT be empty.

o For the cryptographic function ECCSI-ADDR, ID is the concatenation
of an address (in network byte order) and the element <key-id>
defined in Section 12.1 of [RFC7182], where the latter MAY be
empty.

* For a Packet TLV, this address is the IP source address of the
IP datagram in which this packet is included.

* For a Message TLV or an Address Block TLV, this address is the
message originator address (the element <msg-orig-addr> defined
in [RFC5444]) if that address is present; if it is not present
and the message is known to have traveled only one hop, then
the IP source address of the IP datagram in which this message
is included is used. Otherwise, no address is defined and the
message MUST be rejected. (Note that HELLO messages specified
in NHDP [RFC6130] and used in OLSRv2 [RFC7181] always only
travel one hop; hence, their IP source address SHOULD be used
if no originator address is present.)

The element <key-id> MAY be (for the cryptographic function ECCSI-
ADDR) or include (for either cryptographic function) a representation
of the identity expiry time. This MAY use one of the representations
of time defined for the TIMESTAMP TLV in [RFC7182]. A RECOMMENDED
approach is to use the cryptographic function ECCSI-ADDR with element
<key-id> containing the single octet representing the type of the
time, normally used as the TIMESTAMP TLV Type Extension (defined in
[RFC7182], Table 9), or any extension thereof, followed by the time
as so represented, normally used as the TIMESTAMP TLV Value.

Note that the identity is formatted as specified in [RFC6507] and
thus does not need a length field incorporated into it by this
specification.

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5. IANA Considerations

IANA has allocated the following two new values in the "Cryptographic
Functions" registry under "Mobile Ad Hoc NETwork Parameters" registry
and modified the unassigned range accordingly.

+-------+------------+----------------------------------+-----------+
| Value | Algorithm | Description | Reference |
+-------+------------+----------------------------------+-----------+
| 7 | ECCSI | ECCSI [RFC6507] | RFC 7859 |
| 8 | ECCSI-ADDR | ECCSI [RFC6507] with an address | RFC 7859 |
| | | (source or originator) joined to | |
| | | identity | |
| 9-251 | | Unassigned; Expert Review | |
+-------+------------+----------------------------------+-----------+

Table 1: Cryptographic Function Registry

6. Security Considerations

This specification extends the security framework for MANET routing
protocols specified in [RFC7182] by adding cryptographic functions
(in two forms, according to how identity is specified).

This cryptographic function implements a form of IBS; a stronger form
of ICV that verifies not just that the received packet or message is
valid but that the packet or message originated at a router that was
assigned a private key for the specified identity.

It is recommended that the identity include an address unique to that
router: for a message, its originator address, and for a packet, the
corresponding IP packet source address. If additional information is
included in the identity, this may be to indicate an expiry time for
signatures created using that identity.

In common with other forms of IBS, a feature of the form of IBS
(known as ECCSI) used in this specification is that it requires a
trusted KMS that issues all private keys and has complete
cryptographic information about all possible private keys. However,
to set against that, the solution is scalable (as all routers can be
independently keyed) and does not need the KMS in the network. If no
future keys will be required, then the KMS's master secret can be
destroyed. As routers are individually keyed, key revocation (by
blacklist and/or time expiry of keys) is possible.

ECCSI is based on elliptic curve mathematics. This specification
follows [RFC6507] in its recommendation of elliptic curves, but any
suitable (prime power) elliptic curve may be used; this must be

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administratively specified. Implementation of this specification
will require an available implementation of suitable mathematical
functions. Unlike some other forms of IBS, ECCSI requires only basic
elliptic curve operations; it does not require "pairings" (bilinear
functions of a product of two elliptic curve groups). This increases
the available range of suitable mathematical libraries.

6.1. Experimental Status

The idea of using identity-based signatures for authentication of ad
hoc network signaling goes back at least as far as 2005 [Dearlove].
The specific implementation of an IBS used in this specification,
ECCSI, was published as an Internet Draft in 2010 before publication
as an Informational RFC [RFC6507]. ECCSI is now part of standards
such as [ETSI] for LTE Proximity-based Services. An open-source
implementation of cryptographic software that includes ECCSI is
available, see [SecureChorus].

However, although this specification has been implemented for use in
an OLSRv2 [RFC7181] routed network, there are only limited reports of
such use. There are also no reports of the use of ECCSI within the
IETF, other than in this specification. There are no reports of
independent public scrutiny of the algorithm, although ECCSI is
reported [RFC6507] as being based on [ECDSA] with similar properties.

This specification is thus published as Experimental in order to
encourage its use and encourage reports on its use. Once experiments
have been carried out and reported on (and when some public analysis
of the underlying cryptographic algorithms is available), it is
intended to advance this specification, with any changes identified
by such experimentation and analysis, to Standards Track.

7. References

7.1. Normative References

[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.

[RFC5444] Clausen, T., Dearlove, C., Dean, J., and C. Adjih,
"Generalized Mobile Ad Hoc Network (MANET) Packet/Message
Format", RFC 5444, DOI 10.17487/RFC5444, February 2009,
<http://www.rfc-editor.org/info/rfc5444>.

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[RFC6507] Groves, M., "Elliptic Curve-Based Certificateless
Signatures for Identity-Based Encryption (ECCSI)",
RFC 6507, DOI 10.17487/RFC6507, February 2012,
<http://www.rfc-editor.org/info/rfc6507>.

[RFC7182] Herberg, U., Clausen, T., and C. Dearlove, "Integrity
Check Value and Timestamp TLV Definitions for Mobile Ad
Hoc Networks (MANETs)", RFC 7182, DOI 10.17487/RFC7182,
April 2014, <http://www.rfc-editor.org/info/rfc7182>.

7.2. Informative References

[Dearlove] Dearlove, C., "OLSR Developments and Extensions",
Proceedings of the 2nd OLSR Interop and Workshop, July
2005, <http://interop.thomasclausen.org/Interop05/Papers/
Papers/paper-01.pdf>.

[ECDSA] American National Standards Institute, "Public Key
Cryptography for the Financial Services Industry: The
Elliptic Curve Digital Signature Algorithm (ECDSA)",
ANSI X9.62-2005, November 2005.

[ETSI] ETSI/3GPP, "Universal Mobile Telecommunications System
(UMTS); LTE; Proximity-based Services (ProSe); Security
aspects", ETSI TS 33.303, V13.2.0, Release 13, January
2016, <http://www.etsi.org/deliver/
etsi_ts/133300_133399/133303/13.02.00_60/
ts_133303v130200p.pdf>.

[NIST-FIPS-186-4]
National Institute of Standards and Technology, "Digital
Signature Standard (DSS)", FIPS 186-4,
DOI 10.6028/NIST.FIPS.186-4, July 2013.

[NIST-SP-800-57]
National Institute of Standards and Technology,
"Recommendation for Key Management - Part 1: General
(Revision 3)", NIST Special Publication 800-57, Part 1,
Revision 3, DOI 10.6028/NIST.SP.800-57pt1r4, July 2012.

[RFC5497] Clausen, T. and C. Dearlove, "Representing Multi-Value
Time in Mobile Ad Hoc Networks (MANETs)", RFC 5497,
DOI 10.17487/RFC5497, March 2009,
<http://www.rfc-editor.org/info/rfc5497>.

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[RFC6130] Clausen, T., Dearlove, C., and J. Dean, "Mobile Ad Hoc
Network (MANET) Neighborhood Discovery Protocol (NHDP)",
RFC 6130, DOI 10.17487/RFC6130, April 2011,
<http://www.rfc-editor.org/info/rfc6130>.

[RFC7181] Clausen, T., Dearlove, C., Jacquet, P., and U. Herberg,
"The Optimized Link State Routing Protocol Version 2",
RFC 7181, DOI 10.17487/RFC7181, April 2014,
<http://www.rfc-editor.org/info/rfc7181>.

[SecureChorus]
"Secure Chorus: Interoperable and secure enterprise
communications", <http://www.securechorus.com/>.

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Appendix A. Example

Appendix C of [RFC6130] contains this example of a HELLO message.
(Note that normally a TIMESTAMP ICV would also be added before the
ICV TLV, but for simplicity, that step has been omitted here.)

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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| HELLO | MF=7 | MAL=3 | Message Length = 45 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Hop Limit = 1 | Hop Count = 0 | Message Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Message TLV Block Length = 8 | VALIDITY_TIME | MTLVF = 16 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Value Len = 1 | Value (Time) | INTERVAL_TIME | MTLVF = 16 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Value Len = 1 | Value (Time) | Num Addrs = 5 | ABF = 128 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Head Len = 3 | Head |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Mid 0 | Mid 1 | Mid 2 | Mid 3 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Mid 4 | Address TLV Block Length = 14 | LOCAL_IF |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ATLVF = 80 | Index = 0 | Value Len = 1 | THIS_IF |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LINK_STATUS | ATLV = 52 | Strt Indx = 1 | Stop Indx = 4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Value Len = 4 | HEARD | HEARD | SYMMETRIC |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LOST |
+-+-+-+-+-+-+-+-+

In order to provide an example of an ECCSI ICV Message TLV that may
be added to this message, the fields shown need to all have numerical
values, both by inserting defined numerical values (e.g., 0 for
HELLO) and by selecting example values where needed. The latter
means that

o The message sequence number will be zero.

o The five addresses will be 192.0.2.1 to 192.0.2.5.

o The message validity time will be six seconds and the message
interval time will be two seconds, each encoded with a constant
value C = 1/1024 seconds (as described in [RFC5497] and as
referenced from [RFC6130]).

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In addition, when calculating an ICV, the hop count and hop limit are
both set to zero. This results in the message:

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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0 0 0 0 0 0 0 0|0 1 1 1 0 0 1 1|0 0 0 0 0 0 0 0 0 0 1 0 1 1 0 1|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0 0 0 0 0 0 0 0|0 0 0 0 0 0 0 0|0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0|0 0 0 0 0 0 0 1|0 0 0 1 0 0 0 0|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0 0 0 0 0 0 0 1|0 1 1 0 0 1 0 0|0 0 0 0 0 0 0 0|0 0 0 1 0 0 0 0|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0 0 0 0 0 0 0 1|0 1 0 1 1 0 0 0|0 0 0 0 0 1 0 1|1 0 0 0 0 0 0 0|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0 0 0 0 0 0 1 1|1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0 0 0 0 0 0 0 1|0 0 0 0 0 0 1 0|0 0 0 0 0 0 1 1|0 0 0 0 0 1 0 0|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0 0 0 0 0 1 0 1|0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 0|0 0 0 0 0 0 1 0|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0 1 0 1 0 0 0 0|0 0 0 0 0 0 0 0|0 0 0 0 0 0 0 1|0 0 0 0 0 0 0 0|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0 0 0 0 0 0 1 1|0 0 1 1 0 1 0 0|0 0 0 0 0 0 0 1|0 0 0 0 0 1 0 0|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0 0 0 0 0 1 0 0|0 0 0 0 0 0 1 0|0 0 0 0 0 0 1 0|0 0 0 0 0 0 0 1|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0 0 0 0 0 0 0 0|
+-+-+-+-+-+-+-+-+

Or, in hexadecimal form:

M := 0x 0073002D 00000000 00080110 01640010
01580580 03C00002 01020304 05000E02
50000100 03340104 04020201 00

The ICV TLV that will be added will have cryptographic function
ECCSI-ADDR and hash function SHA-256. This message has no originator
address, but it travels a single hop and its IP source address can be
used. This will be assumed to be 192.0.2.0 with an empty <key-id>;
thus, the sender's identity will be (in hexadecimal form):

ID := 0x C0000200

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Parameters for [RFC6507] will thus be n = 256, N = 32. The same
parameters and master key will be used as in Appendix A of [RFC6507],
i.e., the elliptic curve P-256, with parameters:

p := 0x FFFFFFFF 00000001 00000000 00000000
00000000 FFFFFFFF FFFFFFFF FFFFFFFF

B := 0x 5AC635D8 AA3A93E7 B3EBBD55 769886BC
651D06B0 CC53B0F6 3BCE3C3E 27D2604B

q := 0x FFFFFFFF 00000000 FFFFFFFF FFFFFFFF
BCE6FAAD A7179E84 F3B9CAC2 FC632551

G := 0x 04
6B17D1F2 E12C4247 F8BCE6E5 63A440F2
77037D81 2DEB33A0 F4A13945 D898C296
4FE342E2 FE1A7F9B 8EE7EB4A 7C0F9E16
2BCE3357 6B315ECE CBB64068 37BF51F5

KSAK := 0x 12345;

KPAK := 0x 04
50D4670B DE75244F 28D2838A 0D25558A
7A72686D 4522D4C8 273FB644 2AEBFA93
DBDD3755 1AFD263B 5DFD617F 3960C65A
8C298850 FF99F203 66DCE7D4 367217F4

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RFC 7859 Identity-Based Signatures May 2016

The remaining steps to creating a private key for the ID use the same
"random" value v as Appendix A of [RFC6507] and are:

v := 0x 23456

PVT := 0x 04
758A1427 79BE89E8 29E71984 CB40EF75
8CC4AD77 5FC5B9A3 E1C8ED52 F6FA36D9
A79D2476 92F4EDA3 A6BDAB77 D6AA6474
A464AE49 34663C52 65BA7018 BA091F79

HS := hash( 0x 04
6B17D1F2 E12C4247 F8BCE6E5 63A440F2
77037D81 2DEB33A0 F4A13945 D898C296
4FE342E2 FE1A7F9B 8EE7EB4A 7C0F9E16
2BCE3357 6B315ECE CBB64068 37BF51F5
04
50D4670B DE75244F 28D2838A 0D25558A
7A72686D 4522D4C8 273FB644 2AEBFA93
DBDD3755 1AFD263B 5DFD617F 3960C65A
8C298850 FF99F203 66DCE7D4 367217F4
C0000200
04
758A1427 79BE89E8 29E71984 CB40EF75
8CC4AD77 5FC5B9A3 E1C8ED52 F6FA36D9
A79D2476 92F4EDA3 A6BDAB77 D6AA6474
A464AE49 34663C52 65BA7018 BA091F79 )

= 0x F64FFD76 D2EC3E87 BA670866 C0832B80
B740C2BA 016034C8 1A6F5E5B 5F9AD8F3

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RFC 7859 Identity-Based Signatures May 2016

The remaining steps to creating a signature for M use the same
"random" value j as Appendix A of [RFC6507] and are:

j := 0x 34567

J := 0x 04
269D4C8F DEB66A74 E4EF8C0D 5DCC597D
DFE6029C 2AFFC493 6008CD2C C1045D81
6DDA6A13 10F4B067 BD5DABDA D741B7CE
F36457E1 96B1BFA9 7FD5F8FB B3926ADB

r := 0x 269D4C8F DEB66A74 E4EF8C0D 5DCC597D
DFE6029C 2AFFC493 6008CD2C C1045D81

HE := hash( 0x
F64FFD76 D2EC3E87 BA670866 C0832B80
B740C2BA 016034C8 1A6F5E5B 5F9AD8F3
269D4C8F DEB66A74 E4EF8C0D 5DCC597D
DFE6029C 2AFFC493 6008CD2C C1045D81
0073002D 00000000 00080110 01640010
01580580 03C00002 01020304 05000E02
50000100 03340104 04020201 00 )

= 0x FE236B30 CF72E060 28E229ED 5751D796
91DED33C 24D2F661 28EA0804 30D8A832

s' := 0x C8C739D5 FB3EFB75 221CB818 8CAAB86A
2E2669CF 209EA622 7D7072BA A83C2509

s := 0x C8C739D5 FB3EFB75 221CB818 8CAAB86A
2E2669CF 209EA622 7D7072BA A83C2509

Signature := 0x 269D4C8F DEB66A74 E4EF8C0D 5DCC597D
DFE6029C 2AFFC493 6008CD2C C1045D81
C8C739D5 FB3EFB75 221CB818 8CAAB86A
2E2669CF 209EA622 7D7072BA A83C2509
04
758A1427 79BE89E8 29E71984 CB40EF75
8CC4AD77 5FC5B9A3 E1C8ED52 F6FA36D9
A79D2476 92F4EDA3 A6BDAB77 D6AA6474
A464AE49 34663C52 65BA7018 BA091F79

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RFC 7859 Identity-Based Signatures May 2016

Acknowledgments

The author would like to thank his colleagues who have been involved
in identity-based security for ad hoc networks, including (in
alphabetical order) Alan Cullen, Peter Smith, and Bill Williams. He
would also like to thank Benjamin Smith (INRIA/Ecole Polytechnique)
for independently recreating the signature and other values in
Appendix A to ensure their correctness, and Thomas Clausen (Ecole
Polytechnique) for additional comments.

Author's Address

Christopher Dearlove
BAE Systems Applied Intelligence Laboratories
West Hanningfield Road
Great Baddow, Chelmsford
United Kingdom

Phone: +44 1245 242194
Email: [email protected]
URI: http://www.baesystems.com/

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