23FIWARE OpenSpecification Security Optional_Security_Enablers ContentBasedSecurity
Name
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FIWARE.OpenSpecification.Security.Optional Security Enablers.ContentBasedSecurity
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Chapter
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Security,
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Catalogue-Link to Implementation
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[ Content Based Security]
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Owner
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Thales, Adrian Waller
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23.1Preface
Within this document you find a self-contained open specification of a FI-WARE generic enabler, please consult as well the FI-WARE_Product_Vision, the website on http://www.fi-ware.eu and similar pages in order to understand the complete context of the FI-WARE project.
23.2Copyright
Copyright © 2013-2014 by Thales
23.3Legal Notice
Please check the following Legal Notice to understand the rights to use these specifications.
23.4Overview 23.4.1Description
Content-Based Security (CBS) refers to the concept of protecting data and its metadata at its source and integrating access control in a managed way. The data is protected (e.g. by encrypting or signing) at the time of its creation. The cryptographic means, e.g. the algorithm or key, is chosen according to the sensitivity of the data. Instead of controlling access to the information at processing entities, access to the data is managed by restricting access to the cryptographic material needed to remove protection from the data. This type of content protection allows the data to be freely distributed over the physical networks.
The Content Based Security Optional Generic Enabler (OGE) API provides services that protect and remove protection from data. It has three services: the Producer, the Consumer and the Broker. The Producer protects the data by encrypting and/or signing the data, depending on which operations were requested. Each Producer has a relationship with a Broker, which is referred to as the producer's native key broker. When this relationship is established (which may be an offline process), they exchange keys. This enables the key broker to be able to regenerate the keys used to protect containers.
The Consumer is used to remove protection from the content of digital containers by applying a decryption algorithm and/or verifying the digital signature. Each Consumer has a relationship with a Broker, which is referred to as the consumer's native broker. A Consumer applies to its native broker for the digital container’s decryption key.
Brokers process each request for a decryption key by using the Access Control GE and user credentials obtained from the Identity Management GE to reach an automated decision on whether to grant the container consumer access to the decryption key. A Consumer is only able to open the digital container and view its contents if the key broker provides the decryption key.
Content Based Security OGE Block Diagram
A Security Domain is a collection of Producers and Consumers that have a relationship with a single Broker. The CBS OGE is able to support deployments consisting of more than one security domain. A Broker can only regenerate keys for containers that were protected by Producers in its security domain. If a key request relates to a digital container that was generated by a Producer in a different Security Domain, the broker refers the request to the Producer’s native broker. This implies that trust relationships must exist between key brokers in different Security Domains. However, trust relationships between container producers and container consumers (either in the same Security Domain, or in different domains) are not necessary; hence the solution is scalable to large numbers of producers and consumers.
Support for multiple domains is important where data produced by one enterprise is protected and then made available for consumption by other enterprises. To support this model, the concept of a referred key request is introduced. This involves an instance of the CBS OGE in one domain referring a request for a container decrypt key to an instance of the CBS OGE in another domain. The mechanics of the multi domain model are show in the figure below and are described below, using the example of Enterprise A producing containers that are subsequently consumed by Enterprise B.
Multi-domain
23.4.3Target Usage
The Content Based Security OGE is used to apply protection, e.g. encryption and/or signing, at the application layer to items of data (mp3, jpeg, .doc, etc.). It controls access to content in an information container, rather than controlling possession of the information container. This provides:
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Medium, content and channel independent protection
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Protection at rest or in flight
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Fine-grained control
It cryptographically attaches metadata to the protected data items to give:
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Cradle to grave protection
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Sticky policies
It controls access using policy based authorisation so that:
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I let you have the key for information I want to share with you
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I just let you see the metadata for information I don’t want to share with you
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I put the information that I don’t want you to know that I’ve got inside another layer of protection
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