Team Wolf

Distributed, Consistent and

Secure USB StorageMidyear Design Review

Eddie LaiMatt DubeSean BuschZhou Zheng

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Outline PDR Summary Design Implementation Proposed MDR Deliverables Demonstration CDR Deliverables

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Project Summary A device that distributes backups

across several USB drives Maintains consistency as long as

the backups are conflict free Distributes backups to devices

interfaced across a network Requires minimal user input

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Secure Application (k, n) threshold scheme Requires a subset, k, of a set, n, to recover data With fewer than k pieces, no information about the data can

be recovered

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Project Design Implementation Parts to be implemented

• Custom Software• Network Interface• PC interface

Rest provided by Atom development board

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Custom Software Sending hub

• Save listing of checksum, timestamps, and folder paths at one time• Save listing at a later time and “diff” the two records• Process changes and send to other hubs

Receiving hub• Record the “USB Network” from the received update• Iterate through each USB to check if they belong to the USB Network• Distribute updates

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Network Interface TCP/IP socket connection over a LAN

• Unsecure

Client/server model• Server – wait for connection from client with update messages• Client – connect to server, send update messages, then disconnect

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PC Interface Hub should appear as a USB mass storage device

• Hub must act as a USB device (slave) to PC (master)

Developing this interface has been a significant challenge• USB protocol deliberately very uneven

− Most of the software and hardware located on host side− Not meant for PC to PC (host to host) data transfer

• Atom development board only contains USB host ports− Would require additional hardware and drivers

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PC Interface Solutions Bridge cable

• Cable with USB A at each end• Embedded system in-between• Enables PC to PC file transfer

I2C USB slave adapter• Philips ISP1301 USB OTG• Would allow the Atom to interface with USB physical layer• Requires additional hardware and overhead

Different embedded system• Beagle Board

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Beagle Board Low power, low cost system on chip Slight reduction in performance vs Atom

• ARM ® Cortex TM -A8 MHz at 1 GHz• 512MB of low-power DDR RAM

Tiny 3.25" × 3.25" footprint 4 USB hosts and 1 USB OTG 2.0 port

• OTG port allows board to act as USB device• Would handle same number of USB drives as atom board• $149.99 price point

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Proposed MDR Deliverables 2 hubs based on Advantech Intel Atom board Initialize and authenticate hubs to each other

− Authenticate USBs to hub-network

Detect and distribute updates

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Demonstration

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Performance Data

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Performance Data

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Proposed CDR Deliverables PC interface

• Hub will appear to user’s PC as single USB Mass Storage Device

Secure socket connections User interface for initializing and configuring the system

• User should be able to use web browser to access interface

Physical user interaction with hub• Buttons to initiate sync and ejections• LEDs to indicate sync in progress and when its ok to eject

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Questions