Browse Prior Art Database

Method of Preventing Transfer of Database Data Via an Unauthorized Method

IP.com Disclosure Number: IPCOM000037076D
Original Publication Date: 1989-Nov-01
Included in the Prior Art Database: 2005-Jan-29
Document File: 3 page(s) / 52K

Publishing Venue

IBM

Related People

Arnold, HH: AUTHOR [+2]

Abstract

Disclosed is a method to prevent circumvention of system authorization checking by unauthorized transfer of protected data to an unsecured system.

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Method of Preventing Transfer of Database Data Via an Unauthorized Method

Disclosed is a method to prevent circumvention of system authorization checking by unauthorized transfer of protected data to an unsecured system.

BACKGROUND: In OS/2* EE Database Management, the need exists to prevent users from easily browsing database files. Since the OS/2 SE Operating System does not provide a secure file system, the only way to accomplish this is to encode data in the files so that the user cannot interpret it using generally available editors and browse programs. Likewise, a means is needed to prevent user-written applications from accessing database data that may be addressable in the database manager's memory.

The Database Management provides a set of services to support the objectives of preventing database data from being browsed by a program running in a database server. This is accomplished by masking both data contained on the server's database disk files and certain sensitive data being used in memory. Masking is a faster, less secure, technique for preventing casual browsing database files and data. Classical encryption of database files, though more secure, entails a severe performance hit. Functions provided by Database Management allow the buffer pool manager to mask data prior to being written to disk, and to unmask data on request of database functions. Parameters for both the mask data and unmask data operations are a database unique seed and a pointer to the data area to be masked. At database initialization time (first user to connect) masking services initialization is called and is passed the database seed, acquired from the database configuration file. At this time, masking services will use the seed to build a mask for use in masking that database. The mask will be constructed via use of the database seed and a random number generator. In addition to bytes in the mask being random based on the database seed, each byte, if zero, will be forced to a non-zero value by ORing two bits into the byte.

When masking services is called to mask data, the generated mask is used and is XORed (exclusive ORed) into the data byte by byte. If the data being masked is longer than the database mask, the mask is wrapped to begin again from the first byte in the mask. To unmask the data, the same operation is again performed on the masked data. rized transfer of database data between systems (nodes). This makes itdesirable for data on one node to be masked differently when that data is copied to a different node by an unauthorized method.

When database tables are transferred between nodes using authorized means (i.e., Backup/Restore), the database provides authorization checking to assure that the trans...