Radio Frequency Identification (RFID) technology allows automatic data capture from tagged objects moving in a supply chain. This data can be very useful if it is used to answer traceability queries, however it is distributed across many different repositories, owned by different companies. Discovery Services (DS) are designed to assist in retrieving the RFID data relevant for traceability queries while enforcing sharing policies that are defined and required by participating companies to prevent sensitive data from being exposed. In this paper we define an interface for Supply Chain Authorization (SC-Az) and describe the implementation of two visibility restriction mechanisms based on Access Control Lists (ACLs) and Capabilities. Both approaches were converted to the standard eXtensible Access Control Markup Language (XACML) and their correctness and performance was evaluated for supply chains with increasing size.

1. Enforcing RFID Data Visibility Restrictions
using XACML security policies
Miguel Pardal, Mark Harrison, Sanjay Sarma, José Alves Marques
Técnico Lisboa, University of Cambridge, Massachusetts Institute of Technology
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2. Traceability systems assessment framework
http://trakchain.net
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3. Each individual item takes a unique path...
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4. Traceability data security
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5. SCAz – Supply Chain Authorization Language
• Classical authorization mechanisms
- EAC – Enumerated Access Control
• Access control lists
- CCT – Chain of Communication Tokens
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6. Externalized security
• Authentication
- SAML
• Message level (cryptographic) protection
- TLS
• Authorization
- XACML
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7. eXtensible Access Control Markup Language
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8. XACML request processing
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9. Performance assessment tool
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10. EAC processing time breakdown for request evaluation
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11. EAC and CCT evaluation time with increasing item numbers
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12. Contributions
• Data sharing policies
• XACML translation
• Correctness check
• Performance assessment
• Future work
- Pharma pedigree case study
- Combine approaches in expressive language
- “Automatic” authorization
• minimize admin burden for traceability data sharing
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13. Merci! Visit http://trakchain.net
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