Accession Number:

ADA278953

Title:

Security and Privacy for Partial Order Time

Descriptive Note:

Research rept.

Corporate Author:

CARNEGIE-MELLON UNIV PITTSBURGH PA DEPT OF COMPUTER SCIENCE

Personal Author(s):

• Smith, S. W.
• Tygar, J. D.

Report Date:

1994-04-01

Pagination or Media Count:

25.0

Abstract:

Partial order time expresses issues central to many problems in asynchronous distributed systems, but suffers from inherent security and privacy risks. Secure partial order clocks provide a general method to develop application protocols that transparently protect against these risks. Our previous Signed Vector Timestamp protocol provides a partial order time service with some security no one can forge dependence on an honest process. However, that protocol still permits some forgery of dependence, permits all denial of precedence, and leaks private information. This paper uses secure coprocessors to improve the vector protocol our new Sealed Vector Timestamp protocol detects both the presence and absence of causal paths even in the presence of malicious processes, and protects against some privacy risks as well. By solving these previously open security problems. our new protocol provides a foundation for incorporating security and privacy into distributed application protocols based on partial order time.

Descriptors:

• *DATA PROCESSING SECURITY
• *ASYNCHRONOUS COMPUTERS
• RISK
• CLOCKS
• TIME
• PROTECTION
• PATHS
• DISTRIBUTED DATA PROCESSING

Subject Categories:

• Computer Systems Management and Standards

Distribution Statement:

APPROVED FOR PUBLIC RELEASE