RFC 6045
Real-time Inter-network Defense (RID)
6. Security Considerations
Communication between NPs' RID systems must be protected. RID has many security considerations built into the design of the protocol, several of which are described in the following sub-sections. For a complete view of security, considerations need to include the availability, confidentiality, and integrity concerns for the transport, storage, and exchange of information. When considering the transport of RID messages, an out-of-band network, either logical or physical, would prevent outside attacks against RID communication. An out-of-band connection would be ideal, but not necessarily practical. Authenticated encrypted tunnels between RID systems MUST be used to provide confidentiality, integrity, authenticity, and privacy for the data. Trust relationships are based on consortiums and established trust relationships of public key infrastructure (PKI) cross-certifications of consortiums. By using RIDPolicy information, TLS, and the XML security features of encryption [XMLencrypt] and digital signatures [RFC3275], [XMLsig], RID takes advantage of existing security standards. The standards provide clear methods to ensure that messages are secure, authenticated, and authorized, and that the messages meet policy and privacy guidelines and maintain integrity. As specified in the relevant sections of this document, the XML digital signature [RFC3275] and XML encryption [XMLencrypt] are used in the following cases: XML Digital Signature o The originator of the TraceRequest or Investigation request MUST use a detached signature to sign at least one of the original IP packets included in the RecordItem class data to provide authentication to all upstream participants in the trace of the origin. All IP packets provided by the originator may be signed, and additional packets added by upstream peers in the trace may be signed by the peer adding the data, while maintaining the IP packet and detached signature from the original requestor. This signature MUST be passed to all recipients of the TraceRequest. o For all message types, the full IODEF/RID document MUST be signed using an enveloped signature by the sending peer to provide authentication and integrity to the receiving RID system.
XML Encryption
o The IODEF/RID document may be encrypted to provide an extra layer
of security between peers so that the message is not only
encrypted for the transport, but also while stored. This behavior
would be agreed upon between peers or a consortium, or determined
on a per-message basis, depending on security requirements. It
should be noted that there are cases for transport where the
RIDPolicy class needs to be presented in clear text, as detailed
in the transport document [RFC6046].
o An Investigation request, or any other message type that may be
relayed through RID systems other than the intended destination as
a result of trust relationships, may be encrypted for the intended
recipient. This may be necessary if the RID network is being used
for message transfer, the intermediate parties do not need to have
knowledge of the request contents, and a direct communication path
does not exist. In that case, the RIDPolicy class is used by
intermediate parties and is maintained in clear text.
o The action taken in the Result message may be encrypted using the
key of the request originator. In that case, the intermediate
parties can view the RIDPolicy information and know the trace has
been completed and do not need to see the action. If the use of
encryption were limited to sections of the message, the History
class information would be encrypted. Otherwise, it is
RECOMMENDED to encrypt the entire IODEF/RID document, using an
enveloped signature, for the originator of the request. The
existence of the Result message for an incident would tell any
intermediate parties used in the path of the incident
investigation that the incident handling has been completed.
The formation of policies is a very important aspect of using a
messaging system like RID to exchange potentially sensitive
information. Many considerations should be involved for peering
parties, and some guidelines to protect the data, systems, and
transport are covered in this section. Policies established should
provide guidelines for communication methods, security, and fall-back
procedures.
The security considerations for the storage and exchange of
information in RID messaging may include adherence to local,
regional, or national regulations in addition to the obligations to
protect client information during an investigation. RID Policy is a
necessary tool for listing the requirements of messages to provide a
method to categorize data elements for proper handling. Controls are
also provided for the sending entity to protect messages from third
parties through XML encryption.
RID provides a method to exchange incident handling request and Report messages to peer networks. Network administrators, who have the ability to base the decision on the available resources and other factors of their network, maintain control of incident investigations within their own network. Thus, RID provides the ability for participating networks to manage their own security controls, leveraging the information listed in RIDPolicy.6.1. Message Transport
The transport specifications are fully defined in a separate document [RFC6046]. The specified transport protocols MUST use encryption to provide an additional level of security and integrity, while supporting mutual authentication through bi-directional certificate usage. Any subsequent transport method defined should take advantage of existing standards for ease of implementation and integration of RID systems. Session encryption for the transport of RID messages is enforced in the transport specification. The privacy and security considerations are addressed fully in RID to protect sensitive portions of documents and provide a method to authenticate the messages. Therefore, RID messages do not rely on the security provided by the transport layer alone. The encryption requirements and considerations for RID are discussed at the beginning of Section 6 of this document. XML security functions such as the digital signature [RFC3275] and encryption [XMLencrypt] provide a standards-based method to encrypt and digitally sign RID messages. RID messages specify system use and privacy guidelines through the RIDPolicy class. A public key infrastructure (PKI) provides the base for authentication and authorization, encryption, and digital signatures to establish trust relationships between members of a RID consortium or a peering consortium. XML security functions such as the digital signature [RFC3275] and encryption [XMLencrypt] can be used within the contents of the message for privacy and security in cases for which certain elements must remain encrypted or signed as they traverse the path of a trace. For example, the digital signature on a TraceRequest can be used to verify the identity of the trace originator. The use of the XML security features in RID messaging is in accordance with the specifications for the IODEF model; however, the use requirements may differ since RID also incorporates communication of security incident information.
6.2. Message Delivery Protocol - Integrity and Authentication
The RID protocol must be able to guarantee delivery and meet the necessary security requirements of a state-of-the-art protocol. In order to guarantee delivery, TCP should be considered as the underlying protocol within the current network standard practices. Security considerations must include the integrity, authentication, privacy, and authorization of the messages sent between RID communication systems or IHSs. The communication between RID systems must be authenticated and encrypted to ensure the integrity of the messages and the RID systems involved in the trace. Another concern that needs to be addressed is authentication for a request that traverses multiple networks. In this scenario, systems in the path of the multi-hop TraceRequest need to authorize a trace from not only their neighbor network, but also from the initiating RID system as discussed in Section 6.4. Several methods can be used to ensure integrity and privacy of the communication. The transport mechanism selected MUST follow the defined transport protocol [RFC6046] when using RID messaging to ensure consistency among the peers. Consortiums may vary their selected transport mechanisms and thus must decide upon a mutual protocol to use for transport when communicating with peers in a neighboring consortium using RID. RID systems MUST implement and deploy HTTPS as defined in the transport document [RFC6046] and optionally support other protocols such as the Blocks Extensible Exchange Protocol (BEEP). RID, the XML security functions, and transport protocols must properly integrate with a public key infrastructure (PKI) managed by the consortium or one managed by a trusted entity. For the Internet, an example of an existing effort that could be leveraged to provide the supporting PKI could be the American Registry for Internet Numbers (ARIN) and the Regional Internet Registry's (RIR's) PKI hierarchy. Security and privacy considerations related to consortiums are discussed in Sections 6.5 and 6.6.6.3. Transport Communication
Out-of-band communications dedicated to NP interaction for RID messaging would provide additional security as well as guaranteed bandwidth during a denial-of-service attack. For example, an out-of- band channel may consist of logical paths defined over the existing network. Out-of-band communications may not be possible between all network providers, but should be considered to protect the network management systems used for RID messaging. Methods to protect the data transport may also be provided through session encryption.
In order to address the integrity and authenticity of messages, transport encryption MUST be used to secure the traffic sent between RID systems. Systems with predefined relationships for RID would include those who peer within a consortium with agreed-upon appropriate use regulations and for peering consortiums. Trust relationships may also be defined through a bridged or hierarchical PKI in which both peers belong. Systems used to send authenticated RID messages between networks MUST use a secured system and interface to connect to a border network's RID systems. Each connection to a RID system MUST meet the security requirements agreed upon through the consortium regulations, peering, or SLAs. The RID system MUST only listen for and send RID messages on the designated port, which also MUST be over an encrypted tunnel meeting the minimum requirement of algorithms and key lengths established by the consortium, peering, or SLA. The selected cryptographic algorithms for symmetric encryption, digital signatures, and hash functions MUST meet minimum security levels of the times. The encryption strength MUST adhere to import and export regulations of the involved countries for data exchange.6.4. Authentication of RID Protocol
In order to ensure the authenticity of the RID messages, a message authentication scheme is used to secure the protocol. XML security functions utilized in RID require a trust center such as a PKI for the distribution of credentials to provide the necessary level of security for this protocol. Layered transport protocols also utilize encryption and rely on a trust center. Public key certificate pairs issued by a trusted Certification Authority (CA) MAY be used to provide the necessary level of authentication and encryption for the RID protocol. The CA used for RID messaging must be trusted by all involved parties and may take advantage of similar efforts, such as the Internet2 federated PKI or the ARIN/RIR effort to provide a PKI to network providers. The PKI used for authentication would also provide the necessary certificates needed for encryption used for the RID transport protocol [RFC6046]. The use of pre-shared keys may be considered for authentication. If this option is selected, the specifications set forth in "Pre-Shared Key Ciphersuites for Transport Layer Security (TLS)" [RFC4279] MUST be followed. Hosts receiving a RID message MUST be able to verify that the sender of the request is valid and trusted. Using digital signatures on a hash of the RID message with an X.509 version 3 certificate issued by a trusted party MUST be used to authenticate the request. The X.509 version 3 specifications as well as the digital signature
specifications and path validation standards set forth in [RFC5280] MUST be followed in order to interoperate with a PKI designed for similar purposes. The IODEF specification MUST be followed for digital signatures to provide the authentication and integrity aspects required for secure messaging between network providers. The use of digital signatures in RID XML messages MUST follow the World Wide Web Consortium (W3C) recommendations for signature syntax and processing when either the XML encryption [XMLencrypt] or digital signature [XMLsig], [RFC3275] is used within a document. Transport specifications are detailed in a separate document [RFC6046]. It might be helpful to define an extension to the authentication scheme that uses attribute certificates [RFC5755] in such a way that an application could automatically determine whether human intervention is needed to authorize a request; however, the specification of such an extension is out of scope for this document.6.4.1. Multi-Hop TraceRequest Authentication
Bilateral trust relations between network providers ensure the authenticity of requests for TraceRequests from immediate peers in the web of networks formed to provide the traceback capability. A network provider several hops into the path of the RID trace must trust the information from its own trust relationships as well as the previous trust relationships in the downstream path. For practical reasons, the NPs may want to prioritize incident handling events based upon the immediate peer for a TraceRequest, the originator, and the listed Confidence rating for the incident. In order to provide a higher assurance level of the authenticity of the TraceRequest, the originating RID system is included in the TraceRequest along with contact information and the information of all RID systems in the path the trace has taken. This information is provided through the IODEF EventData class nesting the list of systems and contacts involved in a trace, while setting the category attribute to "infrastructure". A second measure MUST be taken to ensure the identity of the originating RID system. The originating RID system MUST include a digital signature in the TraceRequest sent to all systems in the upstream path. The digital signature from the RID system is performed on the RecordItem class of the IODEF following the XML digital signature specifications from W3C [XMLsig] using a detached signature. The signature MUST be passed to all parties that receive a TraceRequest, and each party MUST be able to perform full path validation on the digital signature. Full path validation verifies the chaining relationship to a trusted root and also performs a certificate revocation check. In order to accommodate that requirement, the IP packet in the RecordItem data MUST remain
unchanged as a request is passed along between providers and is the only element for which the signature is applied. If additional packets are included in the document at upstream peers, the initial packet MUST still remain with the detached signature. The subsequent packets may be signed by the peer adding the incident information for the investigation. A second benefit to this requirement is that the integrity of the filter used is ensured as it is passed to subsequent NPs in the upstream trace of the packet. The trusted PKI also provides the keys used to digitally sign the RecordItem class for TraceRequests to meet the requirement of authenticating the original request. Any host in the path of the trace should be able to verify the digital signature using the trusted PKI. In the case in which an enterprise network using RID sends a TraceRequest to its provider, the signature from the enterprise network MUST be included in the initial request. The NP may generate a new request to send upstream to members of the NP consortium to continue the trace. If the original request is sent, the originating NP, acting on behalf of the enterprise network under attack, MUST also digitally sign, with an enveloped signature, the full IODEF document to assure the authenticity of the TraceRequest. An NP that offers RID as a service may be using its own PKI to secure RID communications between its RID system and the attached enterprise networks. NPs participating in the trace MUST be able to determine the authenticity of RID requests.6.5. Consortiums and Public Key Infrastructures
Consortiums of NPs are an ideal way to establish a communication web of trust for RID messaging. The consortium could provide centralized resources, such as a PKI, and established guidelines for use of the RID protocol. The consortium would also assist in establishing trust relationships between the participating NPs to achieve the necessary level of cooperation and experience-sharing among the consortium entities. This may be established through PKI certificate policy [RFC3647] reviews to determine the appropriate trust levels between organizations or entities. The consortium may also be used for other purposes to better facilitate communication among NPs in a common area (Internet, region, government, education, private networks, etc.). Using a PKI to distribute certificates used by RID systems provides an already established method to link trust relationships between NPs of consortiums that would peer with NPs belonging to a separate consortium. In other words, consortiums could peer with other consortiums to enable communication of RID messages between the
participating NPs. The PKI along with Memorandums of Agreement could
be used to link border directories to share public key information in
a bridge, a hierarchy, or a single cross-certification relationship.
Consortiums also need to establish guidelines for each participating
NP to adhere to. The RECOMMENDED guidelines include:
o Physical and logical practices to protect RID systems;
o Network and application layer protection for RID systems and
communications;
o Proper use guidelines for RID systems, messages, and requests; and
o A PKI to provide authentication, integrity, and privacy.
The functions described for a consortium's role would parallel that
of a PKI federation. The PKI federations that currently exist are
responsible for establishing security guidelines and PKI trust
models. The trust models are used to support applications to share
information using trusted methods and protocols.
A PKI can also provide the same level of security for communication
between an end entity (enterprise, educational, or government
customer network) and the NP. The PKI may be a subordinate CA or in
the CA hierarchy from the NP's consortium to establish the trust
relationships necessary as the request is made to other connected
networks.
6.6. Privacy Concerns and System Use Guidelines
Privacy issues raise many concerns when information-sharing is
required to achieve the goal of stopping or mitigating the effects of
a security incident. The RIDPolicy class is used to automate the
enforcement of the privacy concerns listed within this document. The
privacy and system use concerns that MUST be addressed in the RID
system and other integrated components include the following:
Network Provider Concerns:
o Privacy of data monitored and/or stored on IDSs for attack
detection.
o Privacy of data monitored and stored on systems used to trace
traffic across a single network.
Customer Attached Networks Participating in RID with NP:
o Customer networks may include an enterprise, educational,
government, or other attached networks to an NP participating in
RID and MUST be made fully aware of the security and privacy
considerations for using RID.
o Customers MUST know the security and privacy considerations in
place by their NP and the consortium of which the NP is a member.
o Customers MUST understand that their data can and will be sent to
other NPs in order to complete a trace unless an agreement stating
otherwise is made in the service level agreements between the
customer and NP.
Parties Involved in the Attack:
o Privacy of the identity of a host involved in an attack.
o Privacy of information such as the source and destination used for
communication purposes over the monitored or RID connected
network(s).
o Protection of data from being viewed by intermediate parties in
the path of an Investigation request MUST be considered.
Consortium Considerations:
o System use restricted to security incident handling within the
local region's definitions of appropriate traffic for the network
monitored and linked via RID in a single consortium also abiding
by the consortium's use guidelines.
o System use prohibiting the consortium's participating NPs from
inappropriately tracing non-attack traffic to locate sources or
mitigate traffic unlawfully within the jurisdiction or region.
Inter-Consortium Considerations:
o System use between peering consortiums MUST also adhere to any
government communication regulations that apply between those two
regions, such as encryption export and import restrictions. This
may include consortiums that are categorized as
"BetweenConsortiums" or "AcrossNationalBoundaries".
o System use between consortiums MUST NOT request traffic traces and
actions beyond the scope intended and permitted by law or
inter-consortium agreements.
o System use between consortiums classified as
"AcrossNationalBoundaries" MUST respect national boundary issues
and limit requests to appropriate system use and not to achieve
their own agenda to limit or restrict traffic that is otherwise
permitted within the country in which the peering consortium
resides.
The security and privacy considerations listed above are for the
consortiums, NPs, and enterprises to agree upon. The agreed-upon
policies may be facilitated through use of the RIDPolicy class. Some
privacy considerations are addressed through the RID guidelines for
encryption and digital signatures as described at the beginning of
Section 6.
RID is useful in determining the true source of a packet that
traverses multiple networks or to communicate security incidents and
automate the response. The information obtained from the trace may
determine the identity of the source host or the network provider
used by the source of the traffic. It should be noted that the trace
mechanism used across a single-network provider may also raise
privacy concerns for the clients of the network. Methods that may
raise concern include those that involve storing packets for some
length of time in order to trace packets after the fact. Monitoring
networks for intrusions and for tracing capabilities also raises
concerns for potentially sensitive valid traffic that may be
traversing the monitored network. IDSs and single-network tracing
are outside of the scope of this document, but the concern should be
noted and addressed within the use guidelines of the network. Some
IDSs and single-network trace mechanisms attempt to properly address
these issues. RID is designed to provide the information needed by
any single-network trace mechanism. The provider's choice of a
single trace mechanism depends on resources, existing solutions, and
local legislation. Privacy concerns in regard to the single-network
trace must be dealt with at the client-to-NP level and are out of
scope for RID messaging.
The identity of the true source of an attack packet being traced
through RID could be sensitive. The true identity listed in a Result
message can be protected through the use of encryption [XMLencrypt]
enveloping the IODEF document and RID Result information, using the
public encryption key of the originating NP. Alternatively, the
action taken may be listed without the identity being revealed to the
originating NP. The ultimate goal of the RID communication system is
to stop or mitigate attack traffic, not to ensure that the identity
of the attack traffic is known to involved parties. The NP that
identifies the source should deal directly with the involved parties
and proper authorities in order to determine the guidelines for the
release of such information, if it is regarded as sensitive. In some
situations, systems used in attacks are compromised by an unknown source and, in turn, are used to attack other systems. In that situation, the reputation of a business or organization may be at stake, and the action taken may be the only additional information reported in the Result message to the originating system. If the security incident is a minor incident, such as a zombie system used in part of a large-scale DDoS attack, ensuring the system is taken off the network until it has been fixed may be sufficient. The decision is left to the system users and consortiums to determine appropriate data to be shared given that the goal of the specification is to provide the appropriate technical options to remain compliant. The textual descriptions should include details of the incident in order to protect the reputation of the unknowing attacker and prevent the need for additional investigation. Local, state, or national laws may dictate the appropriate reporting action for specific security incidents. Privacy becomes an issue whenever sensitive data traverses a network. For example, if an attack occurred between a specific source and destination, then every network provider in the path of the trace would become aware that the cyber attack occurred. In a targeted attack, it may not be desirable that information about two nation states that are battling a cyber war would become general knowledge to all intermediate parties. However, it is important to allow the traces to take place in order to halt the activity since the health of the networks in the path could also be at stake during the attack. This provides a second argument for allowing the Result message to only include an action taken and not the identity of the offending host. In the case of an Investigation request, where the originating NP is aware of the NP that will receive the request for processing, the free-form text areas of the document could be encrypted [XMLencrypt] using the public key of the destination NP to ensure that no other NP in the path can read the contents. The encryption would be accomplished through the W3C [XMLencrypt] specification for encrypting an element. In some situations, all network traffic of a nation may be granted through a single network provider. In that situation, options must support sending Result messages from a downstream peer of that network provider. That option provides an additional level of abstraction to hide the identity and the NP of the identified source of the traffic. Legal action may override this technical decision after the trace has taken place, but that is out of the technical scope of this document. Privacy concerns when using an Investigation request to request action close to the source of valid attack traffic needs to be considered. Although the intermediate NPs may relay the request if
there is no direct trust relationship to the closest NP to the source, the intermediate NPs do not require the ability to see the contents of the packet or the text description field(s) in the request. This message type does not require any action by the intermediate RID systems, except to relay the packet to the next NP in the path. Therefore, the contents of the request may be encrypted for the destination system. The intermediate NPs would only need to know how to direct the request to the manager of the ASN in which the source IP address belongs. Traces must be legitimate security-related incidents and not used for purposes such as sabotage or censorship. An example of such abuse of the system would include a request to block or rate-limit legitimate traffic to prevent information from being shared between users on the Internet (restricting access to online versions of papers) or restricting access from a competitor's product in order to sabotage a business. Intra-consortium RID communications raise additional issues, especially when the peering consortiums reside in different regions or nations. TraceRequests and requested actions to mitigate traffic must adhere to the appropriate use guidelines and yet prevent abuse of the system. First, the peering consortiums MUST identify the types of traffic that can be traced between the borders of the participating NPs of each consortium. The traffic traced should be limited to security-incident-related traffic. Second, the traces permitted within one consortium if passed to a peering consortium may infringe upon the peering consortium's freedom of information laws. An example would be a consortium in one country permitting a trace of traffic containing objectionable material, outlawed within that country. The RID trace may be a valid use of the system within the confines of that country's network border; however, it may not be permitted to continue across network boundaries where such content is permitted under law. By continuing the trace in another country's network, the trace and response could have the effect of improperly restricting access to data. A continued trace into a second country may break the laws and regulations of that nation. Any such traces MUST cease at the country's border. The privacy concerns listed in this section address issues among the trusted parties involved in a trace within an NP, a RID consortium, and peering RID consortiums. Data used for RID communications must also be protected from parties that are not trusted. This protection is provided through the authentication and encryption of documents as they traverse the path of trusted servers. Each RID system MUST perform a bi-directional authentication when sending a RID message and use the public encryption key of the upstream or downstream peer to send a message or document over the network. This means that the
document is decrypted and re-encrypted at each RID system via TLS over the transport protocol [RFC6046]. The RID messages may be decrypted at each RID system in order to properly process the request or relay the information. Today's processing power is more than sufficient to handle the minimal burden of encrypting and decrypting relatively small typical RID messages.7. IANA Considerations
This document uses URNs to describe XML namespaces and XML schemas [XMLschema] conforming to a registry mechanism described in [RFC3688]. Registration request for the iodef-rid namespace: URI: urn:ietf:params:xml:ns:iodef-rid-1.0 Registrant Contact: See the "Author's Address" section of this document. XML: None. Namespace URIs do not represent an XML specification. Registration request for the iodef-rid XML schema: URI: urn:ietf:params:xml:schema:iodef-rid-1.0 Registrant Contact: See the "Author's Address" section of this document. XML: See Section 5, "RID Schema Definition", of this document.8. Summary
Security incidents have always been difficult to trace as a result of the spoofed sources, resource limitations, and bandwidth utilization problems. Incident response is often slow even when the IP address is known to be valid because of the resources required to notify the responsible party of the attack and then to stop or mitigate the attack traffic. Methods to identify and trace attacks near real time are essential to thwarting attack attempts. Network providers need policies and automated methods to combat the hacker's efforts. NPs need automated monitoring and response capabilities to identify and trace attacks quickly without resource-intensive side effects. Integration with a centralized communication system to coordinate the detection, tracing, and identification of attack sources on a single network is essential. RID provides a way to integrate NP resources for each aspect of attack detection, tracing, and source
identification and extends the communication capabilities among network providers. The communication is accomplished through the use of flexible IODEF XML-based documents passed between IHSs or RID systems. A TraceRequest or Investigation request is communicated to an upstream NP and may result in an upstream trace or in an action to stop or mitigate the attack traffic. The messages are communicated among peers with security inherent to the RID messaging scheme provided through existing standards such as XML encryption and digital signatures. Policy information is carried in the RID message itself through the use of the RIDPolicy. RID provides the timely communication among NPs, which is essential for incident handling.9. References
9.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC3275] Eastlake 3rd, D., Reagle, J., and D. Solo, "(Extensible Markup Language) XML-Signature Syntax and Processing", RFC 3275, March 2002. [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, January 2004. [RFC4279] Eronen, P., Ed., and H. Tschofenig, Ed., "Pre-Shared Key Ciphersuites for Transport Layer Security (TLS)", RFC 4279, December 2005. [RFC5070] Danyliw, R., Meijer, J., and Y. Demchenko, "The Incident Object Description Exchange Format", RFC 5070, December 2007. [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. [RFC5755] Farrell, S., Housley, R., and S. Turner, "An Internet Attribute Certificate Profile for Authorization", RFC 5755, January 2010. [RFC6046] Moriarty, K. and B. Trammell, "Transport of Real-Time Inter-Network Defense (RID) Messages," RFC 6046, November 2010.
[XML1.0] "Extensible Markup Language (XML) 1.0 (Second Edition)". W3C Recommendation. T. Bray, E. Maler, J. Paoli, and C.M. Sperberg-McQueen. October 2000. http://www.w3.org/TR/2000/REC-xml-20001006. [XMLnames] "Namespaces in XML 1.0 (Third Edition)". W3C Recommendation. T. Bray, D. Hollander, A. Layman, R. Tobin, H. Thompson. December 2009. http://www.w3.org/TR/REC-xml-names/. [XMLencrypt] "XML Encryption Syntax and Processing". W3C Recommendation. T. Imamura, B. Dillaway, and E. Simon. December 2002. http://www.w3.org/TR/xmlenc-core/. [XMLschema] "XML Schema". E. Van der Vlist. O'Reilly. 2002. [XMLsig] "XML-Signature Syntax and Processing (Second Edition)". W3C Recommendation. M. Bartel, J. Boyer, B. Fox, B. LaMacchia, and E. Simon. June 2008. http://www.w3.org/TR/xmldsig-core/#sec-Design.9.2. Informative References
[RFC1930] Hawkinson, J. and T. Bates, "Guidelines for creation, selection, and registration of an Autonomous System (AS)", BCP 6, RFC 1930, March 1996. [RFC2827] Ferguson, P. and D. Senie, "Network Ingress Filtering: Defeating Denial of Service Attacks which employ IP Source Address Spoofing", BCP 38, RFC 2827, May 2000. [RFC3647] Chokhani, S., Ford, W., Sabett, R., Merrill, C., and S. Wu, "Internet X.509 Public Key Infrastructure Certificate Policy and Certification Practices Framework", RFC 3647, November 2003. [RFC3917] Quittek, J., Zseby, T., Claise, B., and S. Zander, "Requirements for IP Flow Information Export (IPFIX)", RFC 3917, October 2004. [RFC5735] Cotton, M. and L. Vegoda, "Special Use IPv4 Addresses", BCP 153, RFC 5735, January 2010. [IPtrace] "Advanced and Authenticated Marking Schemes for IP Traceback". D. Song and A. Perrig. IEEE INFOCOM 2001.
[HASH-IPtrace] "Hash-Based IP Traceback". A. Snoeren, C. Partridge, L. Sanchez, C. Jones, F. Tchakountio, S. Kent, and W. Strayer. SIGCOMM'01. August 2001. [ICMPtrace] Bellovin, S., Leech, M., and T. Taylor, "ICMP Traceback Messages", Work in Progress, February 2003. [NTWK-IPtrace] "Practical network support for IP traceback". S. Savage, D. Wetherall, A. Karlin, and T. Anderson. SIGCOMM'00. August 2000. [DoS] "Trends in Denial of Service Attack Technology". K. Houle, G. Weaver, N. Long, and R. Thomas. CERT Coordination Center. October 2001.Acknowledgements
Many thanks to coworkers and the Internet community for reviewing and commenting on the document as well as providing recommendations to simplify and secure the protocol: Robert K. Cunningham, Ph.D, Cynthia D. McLain, Dr. William Streilein, Iljitsch van Beijnum, Steve Bellovin, Yuri Demchenko, Jean-Francois Morfin, Stephen Northcutt, Jeffrey Schiller, Brian Trammell, Roman Danyliw, Tony Tauber, and Sandra G. Dykes, Ph.D.Sponsor Information
This work was sponsored by the Air Force under Air Force Contract FA8721-05-C-0002, while working at MIT Lincoln Laboratory. "Opinions, interpretations, conclusions, and recommendations are those of the author and are not necessarily endorsed by the United States Government".Author's Address
Kathleen M. Moriarty RSA, The Security Division of EMC 174 Middlesex Turnpike Bedford, MA 01730 US EMail: Moriarty_Kathleen@EMC.com