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Forensic disk controller
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<p>A forensic disk controller or hardware write-block device is a specialized type of computer <a href="/facts/Hard_disk_controller/dfRSYlMq">hard disk controller</a> made for the purpose of gaining read-only access to computer <a href="/facts/Hard_disk_drive/kekLSGSE">hard drives</a> without the risk of damaging the drive's contents. The device is named <a href="/facts/Forensics/4upVa2vB">forensic</a> because its most common application is for use in investigations where a computer hard drive may contain evidence. Such a controller historically has been made in the form of a <a href="/facts/Dongle/aSvsUF6X">dongle</a> that fits between a computer and an <a href="/facts/Integrated_Drive_Electronics/QPchqXH8">IDE</a> or <a href="/facts/SCSI/pxXulrBr">SCSI</a> hard drive, but with the advent of <a href="/facts/Universal_Serial_Bus/XcIKWLyg">USB</a> and <a href="/facts/Serial_ATA/dW8yAMm8">SATA</a>, forensic disk controllers supporting these newer technologies have become widespread. Steve Bress and Mark Menz invented hard drive write blocking (US Patent 6,813,682). </p><p>A device which is installed between a storage media under investigation and an investigator's computer is called a "bridge kit". The bridge kit has one connector for the storage media and another connector the investigator's computer. It allows the investigator to read, but not alter the device under investigation. </p><p>The United States <a href="/facts/National_Institute_of_Justice/jJW1Wx1t">National Institute of Justice</a> operates a Computer Forensics Tool Testing (CFTT) program which formally identifies the following top-level tool requirements: </p> <blockquote><p>A hardware write block (HWB) device shall not transmit a command to a protected storage device that modifies the data on the storage device. </p><p>An HWB device shall return the data requested by a read operation. </p><p>An HWB device shall return without modification any access-significant information requested from the drive. </p><p> Any error condition reported by the storage device to the HWB device shall be reported to the host.</p></blockquote>