Customer Evaluation and Trends
  HYDATA Software Release Read-Only USB Storage Device
In the current data services industry, they usually promise to offer customers read-only service, but engineers always avoid writing into original media by virtue of industrial experiences. At present some companies have issued physical devices with read-only access, it is not used widely in software industry because of high price. Reading from driver layer using USB read-only driver developed by HYDATA Software can realize source media protection on any PC.

The implementation of read-only of USB media from driver layer can avoid improper human operation, cache of system to disk and malware writing, which can easily create a secure and trusted environment of data recovery.

Software includes public version and official version, and the public version may totally realize USB read-only function, monitoring from driver layer, preventing malware modifying registration device, and open control for USB read-only. The official version mainly focuses on corrupted media. It prevents system loading DBR from driver layer, which can make corrupted device easily access to USB port and avoiding USB stuck due to system enumeration after access.

The following is the realization principles of USB read-only driver (official version):

Read-only driver blocks all write operations to USB storage device using standard WDM (windows driver mode) filter. When mass storage device successfully accessed to USB bus and accomplished enumeration, normally host computer will issue requests sequentially: INDQUIRY; READ CAPACTIY; UFI MODE SENSE. Once a correct result returned, the host will issue READ instruction to read MBR data in Cluster 0 Sector 0 of file system and entering identification phase of file system. But HYDATA Software will issue an empty MBR data to Cluster 0 Sector 0 from driver layer when the host issues READ instruction and reads file system, then entering identification phase of file system in order to make corrupted device accessible. This tool is used to check and recover accessible storage media, and it belongs to top-level filter driver, upward compatible with data recovery software.