Internet DRAFT - draft-chen-rats-usecase
draft-chen-rats-usecase
RATS M. Chen
Internet-Draft Li. Su
Intended status: Informational China Mobile
Expires: July 31, 2021 January 27, 2021
Use Cases for RATS
draft-chen-rats-usecase-03
Abstract
This document presents three scenarios from the Internet Service
Providers' perspective as an supplement use case of the RATS work
group. And make some discussions of access authentication,
application authentication and trusted link. The requirements of
trusted link is put forward to establish a protecttive network
connection, thus ensure the native network security.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Use Cases . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3.1. Access authentication based on different method . . . . . 4
3.2. Application authentication based on different system . . 5
3.3. virtualization-based systems . . . . . . . . . . . . . . 5
3.4. Use case based on trusted routing . . . . . . . . . . . . 6
4. Requirements of trusted link . . . . . . . . . . . . . . . . 7
4.1. New equipment into the network . . . . . . . . . . . . . 7
4.2. Device status updating . . . . . . . . . . . . . . . . . 8
5. Security Considerations . . . . . . . . . . . . . . . . . . . 9
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9
7. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 9
8. Informative References . . . . . . . . . . . . . . . . . . . 9
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9
1. Introduction
At present, it is necessary to complete the authentication before
accessing the operator's network to obtain the service. RATS aimed
at the solutions to provide interoperable way for domain-specific
attestation mechanisms, within RATS relying party may not to maintain
the authentication background, as an ISP what may be involved at the
level of access authentication is preshared secret keys based
authentication, the authentication based on PSK(Preshared secret
keys) is different from identity-based authentication, such as
IBC(Identity-Based Cryptograph).
After access to the network, operators can also provide application
layer authentication services for a variety of applications. At
present, there are many application layer authentication methods, it
can be divided into certificate-based and non-certificate-based
certification systems, so there are the following situations. One
application authenticated by certificate-based PKI system may request
resource access to a server or service, but the server or service's
authentication function is based on identity which is belong to non-
certificate-based certification systems. These are all possible
future demand scenarios, also in the context of the RATS. Due to
limitation of resource, many companies are unable to operate their
own certification and willing to rely on the result from operator to
reduce their cost, and operator can provide authentication services.
Multiple certification centers would be made due to different kinds
of request from service and perspective of deployment, before
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obtaining a certification center's service, certification center need
proof for identification, including software and hardware health
information. These certification centers are based on regions then
there have manage barriers, how can clients from a certification
center asstest themselves' identities to another certification
center. Especially now there are more virtual resources, cloud
resources, one need to prove whether it has access to the resources
and can protect the data. From an internal business perspective, how
to integrate resources, achieve cross-domain trust and break down
management barriers in order to streamline and improve flexibility
will also be something rats[I-D.ietf-rats-architecture] can do.
AS Communication Technology and Internet Technology are converging,
especially mobile communication network have stepped into 5G era,
besides 5G network slice safety needs attention, basic routing is
also need to pay much more attention since damage points of routing
nodes will affect the security of the whole link. In some scenarios
we need to form a trusted routing link. in the internet draft draft-
voit-rats-trustworthy-path-routing-00 also have mentioned this
problem.
A trusted link means that every device on the link is proven to be
trusted dymaticly. In the real world, a new device or a small
network is need to add into the core network, newly added associated
equipments are required Security and Trustworthy. After the
formation of deterministic networks, three problems need to be
solved: how to dynamically check the security of equipment, how to
dynamically select the best route based on business requirements, how
to ensure computing and security capabilities.
2. Terminology
The readers should be familiar with the terms defined in.
In addition, this document makes use of the following terms:
PSK: Preshared secret keys means keys are shared in advance between
the authentication parties.
IBC: Identity-Based Cryptograph, it is an asymmetric public key
cryptosystem.
PKI: Public Key Infrastructure, an infrastructure built with a
public-key mechanism.
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3. Use Cases
This section describes use cases which happens inside an ISP.
3.1. Access authentication based on different method
This section considers the level of access authentication. For
operators, the access of users is usually based on preshared secret
keys, preset with symmetric secret keys before the release. The
first access only needs to be activated, and subsequent
authentication uses PSK to complete data protection which is based on
Symmetric secret key system. In addition, there are other identity-
based authentication methods, the access authentication based on
identity is asymmetric and the identity is the public key, this
approach makes it easier for the peer to obtain the public key of the
other peer.
In short, these are two different authentication methods. When a
psk-based authentication device needs to request an identity-based
service, it needs to prove its' trustworthiness to the other party
and the whole process need to ensure the confidentiality of evidences
and attestation results.
（relying party1) (relying party2)
+---------------+ +---------------+
|PSK Auth_Center| |IBC Auth_Center|
+---------------+ +---------------+
|\ +------------// |
|Evidence /Attestation |
Attestation | / Result |
Result \| / |
+-------------------+ +-------------------+
|App/SIMCard/IoTCard| |App/SIMCard/IoTCard|
+-------------------+ +-------------------+
(attester)
Figure 1: different access authentication methods within RATS
The format and content of the evidence: TBD
The format of the Attestation Result: TBD
The transmission protocol for evidence or attestation result: TBD
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3.2. Application authentication based on different system
At the application level, due to limitation of resource, many
applications need operators to provide business authentication
services. At present, there are two business authentication methods:
one is certification-based PKI system authentication, because the
management of certificates is always a very big problem, so the other
is non-certificated, such as identity-based authentication whose
identity is readable.
When cross-business authentication is required, how to prove one's
identity to the other will be a common problem.
(relying party1) (relying party2)
+-----------------------------------+ +-----------------------------------+
|Application authentication platform| |Application authentication platform|
| based on certificate |-----| based on non-certificate |
+-----------------------------------+ +-----------------------------------+
| {Attestation} /| |
| { Result } / |
| ---------- |
| / |
+---------------+ +---------------+
| application | | application |
+---------------+ +---------------+
(attester1) (attester2)
Figure 2: different application authentication methods in RATS architecture
The format and content of the evidence: TBD
The format of the Attestation Result: TBD
The transmission protocol for evidence or attestation result: TBD
Certification-based authentication process: TBD
Identity-based authentication process: TBD
3.3. virtualization-based systems
Cloud computing and other virtualized environment also need remote
attestation, one service offered through cloud computing is
Infrastructure as a Service (IaaS), which provides virtualized
computing resources to enterprises, typically over the Internet. The
virtualization platform or virtualization system needs to provide
evidence to the user or third party, the process may involve vTPM,
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which support for establishing trust in a virtualized environment,
especially remote verification of software integrity.
3.4. Use case based on trusted routing
5G provides security slices based on routing security, routing
devices can be hijacked because of vulnerabilities, damaged equipment
could be monitored, so ISP need to be able to dynamically retrieve
the status of routing devices, according to the state of the devices
dynamicly form a safety link, RATS needs to be used in this case.
There are two scenarios for this case: a trusted link is formed
within a single operator and a trusted link is formed across
operators. The default prerequisite is routing devices support TPM
or other relevant standard.
+---------------------------------+
| |
| Trusted Identification System |
| |
+-------- -------^--+-------------+
| |
| |
| |
Device Conditions | | Latest trusted status
(evidence)or | |
(Appraisal results)| |
| |
+-----------------+ | | +------------------+
| | | | | |
| Routing Device +------------+ +----------> Orchestrator |
| | | |
+-----------------+ +--------+---------+
|
v
Form a routing path
Figure 3: a trusted link is formed within an ISP in RATS
ISP A ISP B
+-------------------+ +--------------------+
| | Appraisal results | |
| Trusted Path +-------------------------^+ Trusted Path |
| <--------------------------+ |
+-------------------+ cross-domain trusted link+--------------------+
Figure 4: a trusted link is formed between ISPs in RATS
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4. Requirements of trusted link
From the operator's point of view, a more secure link capability will
be more competitive for external service. Therefore, Operators
attach great importance to the innate security of links, the links
innate security highly relied on each networking device that is the
routing equipment.
4.1. New equipment into the network
How to add a new device to the network without the consideration of
trustworthiness? new routing devices go through four steps before
they are actually added to the network, step 1: manually configure
the IP address; step 2: discovery device by broadcast protocol; step
3: Verify the identity of the device; step 4: Device Manager issues
routing configuration policies. After completing these four steps,
the route neighbor is formed.
+------------+
+-------+Orchestrator+---------+
| +----+--+----+ |
| | ^ |
| step2| |step3 |
| step4| | |
| v | |
+--+-+ ++--++ +--+-+
| RT | | RT |step1 | RT |
+----+ +----+ +----+
NEW
Figure 5-1: a new router added to network
How to add a new device to the network with the consideration of
devices' trustworthiness? A trusted link has been formed by default,
when a new equipment apply to join the network, new router should
provide evidences to the verifier, the orchestrator play the role of
verifier, and feed back the attestation result back to the new
router, it depends on the implementation. Provision of evidence and
trustworthiness assessment actually happens in the Step3 which
described in the figure above. After complete the trustworthiness
assessment, the orchestrator forms routing policies based on the
trustworthiness and issues them, the trusted link establishment is
complete.
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+------------------------------------+
| |
| +------------+ |
Step3 | | | Result +----+ |
| |Ochestrator +<-------------> RT | |
| +-----+------+ evidence +----+ |
| | NEW |
+------------------------------------+
|
+--------------+--------------------------+
| +----+ +----+ +----+ |
| | RT +---------+ RT +----------+ RT | |
| +----+ 1 +----+ 2 +----+ |
+-----------------------------------------+
Trusted link
Figure 5-2: a new router added to network
4.2. Device status updating
How to maintain the freshness of trusted links for the network is
always under threat of attack when need to form a trusted link to
provide to the user for transmission. The Ochestrator can collect
routing information in real time or periodically, including device
information, log information, fault information, and trusty measure
vendors. Then Ochestrator forms a path link based on users'
trustworthiness requirements while the whole network has fault
convergence.
+-----------+
|Ochestrator|
+-+--+---+--+
^ ^ ^
| | |
+----------+ | +-----------+
| evidence |
| | |
+--+-+ +-+--+ +-+--+
| RT +---------+ RT +----------+ RT |
+----+ 1 +----+ 2 +----+
Trusted link
Figure 6: a new router added to network
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5. Security Considerations
TBD
6. IANA Considerations
This document does not require any action from IANA.
7. Acknowledgement
TBD
8. Informative References
[I-D.ietf-rats-architecture]
Birkholz, H., Thaler, D., Richardson, M., Smith, N., and
W. Pan, "Remote Attestation Procedures Architecture",
draft-ietf-rats-architecture-08 (work in progress),
December 2020.
Authors' Addresses
Meiling Chen
China Mobile
32, Xuanwumen West
BeiJing, BeiJing 100053
China
Email:
chenmeiling@chinamobile.com
Li Su
China Mobile
32, Xuanwumen West
BeiJing
100053
China
Email:
suli@chinamobile.com
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