Browse Prior Art Database

METHODS FOR ADAPTING THE SCSI INTERFACE FOR USE WITH AN ENCRYPTION MODULE

IP.com Disclosure Number: IPCOM000008326D
Original Publication Date: 1997-Sep-01
Included in the Prior Art Database: 2002-Jun-06
Document File: 4 page(s) / 161K

Publishing Venue

Motorola

Related People

Ferdie Brilantes: AUTHOR [+5]

Abstract

This paper proposes three solutions for interfac- ing an RNC (R~adio Network Controller) to its encryption module via the SCSI (Small Computer System Interface) interface. The first two solutions involve adapting, the Direct Access Device Type to work with an encryption module. The third solution involves the development of a command set supporting encryption modules to be included in the SCSI standard as an Encryption Device Type.

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METHODS FOR ADAPTING THE SCSI INTERFACE FOR USE WITH AN ENCRYPTION MODULE

by Ferdie Brilantes, Ronald Shaffer, Don Beyer, Bhavesh Shah and Brett Srudy

1 .O BACKGROUND

  This paper proposes three solutions for interfac- ing an RNC (R~adio Network Controller) to its encryption module via the SCSI (Small Computer System Interface) interface. The first two solutions involve adapting, the Direct Access Device Type to work with an encryption module. The third solution involves the development of a command set supporting encryption modules to be included in the SCSI standard as an Encryption Device Type.

2.0 METHOD I

  The RNC uses a SCSI driver that supports communication with a Direct Access Device (i.e. Hard Drives, Disk Drives etc.) a universally supported SCSI device type. This device type has to support a command set that is specified by the SCSI standard (e.g. SCSI READ, SCSI WRITE etc.). The command set was specifically designed to allow for storage and retrieval of data to and from specific memory locations. It was not designed to allow for the encryption or decryption of data.

  A Direct Access Device type typically performs WRITES and READS to and from specific memory locations. For example, if an application program wants to store a lile in a SCSI hard drive, it will use the SCSI WRITE command to specify where it

wants to store the data and the length of the data to be stored. An encryption module however is not really a storage device. Therefore, a SCSI WRITE is meaningless to an encryption module. However, if we use the SCSI WRITE and embed the encryp tion request within the data to be written, the encryption module can then parse the received data
(i.e. the data sent using the SCSI WRITE command) to determine the correct action. For example, the received data may contain an opcode that specifically instructs the encryption module to encrypt some number of bytes of the received data. Once the encryption process is complete, the encrypted data can then be retrieved via the SCSI READ command.

3.0 METHOD II

  The SCSI Extended WRITE command block (see Figure I) consists of an opcode field (indicates that it's an extended write), a Logical Block Field (indicates where in memory the write should begin), Transfer Length (indicates the size of the data to be written) and some other misc. fields. Since the encryption module is not a storage device, the logical block does not really mean anything to the encryp- tion module. Therefore, instead of using the Logical Block field to indicate memory location, it can be used as an opcode to indicate what service is being requested (see Figure 2).

L' Motorola. 1°C. ,997 124 September 1997

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