373 results about "Data erasure" patented technology

A system and method for protecting data within a portable electronic device to prevent unauthorized access to that data. Encryption of data within the portable electronic device and automatic erasure of data upon unauthorized attempted access is provided. A limited number of attempts to access the portable electronic device are allowed, and if exceeded, the data is automatically erased without notification. Data transfer functions of the portable electronic device are also disabled when the device is locked. Erasing of data is also provided if the portable electronic device is not synced with another device during a predetermined time period.

An improved Flash memory device with a distributed erase block management (EBM) scheme is detailed that enhances operation and helps minimize write fatigue of the floating gate memory cells of the Flash memory device. In the prior art, erase block management of a Flash memory device, which provides logical sector to physical sector mapping and provides a virtual rewriteable interface for the host, requires that erase block management data be kept in specialized EBM data tables to keep the state of the Flash memory device in case of loss of power. This placement of EBM data in a separate erase block location from the user data slows the Flash memory operation by requiring up to two writes and/or block erasures for every update of the user data. Additionally, one of the goals of the EBM control is to minimize write fatigue of the non-volatile floating gate memory cells of the Flash memory device erase blocks by re-mapping and distributing heavily rewritten user data sectors in a process called load leveling so that no one erase block gets overused too quickly and reduce the expected lifespan of the Flash memory device. The EBM data structures, however, are some of the most heavily rewritten non-volatile floating gate memory cells in the device and thus, while helping to reduce write fatigue in the Flash memory device, are some of the data structures most susceptible to the process of fatigue. The Flash memory device of the invention combines the EBM data in a user data erase block by placing it in an EBM data field of the control data section of the erase block sectors. Therefore distributing the EBM data within the Flash memory erase block structure. This allows the Flash memory to update and/or erase the user data and the EBM data in a single operation, to reduce overhead and speed operation. The Flash memory also reduces the process of EBM data structure write fatigue by allowing the EBM data fields to be load leveled by rotating them with the erase blocks they describe.

A non-volatile semiconductor memory device includes: a memory cell array having NAND strings arranged therein, each NAND string having a plurality of electrically rewritable and non-volatile memory transistors connected in series; and an erase/write/read control circuit configured to perform erasing, writing and reading of the memory cell array, wherein at least one memory transistor within each NAND string of the memory cell array is controlled as a block separation transistor for dividing the memory cell array into a plurality of blocks each serving as a unit of data erasure.

This disclosure concerns a memory including: a first memory region including memory groups including a plurality of memory cells, addresses being respectively allocated for the memory groups, the memory groups respectively being units of data erase operations; a second memory region temporarily storing therein data read from the first memory region or temporarily storing therein data to be written to the first memory region; a read counter storing therein a data read count for each memory group; an error-correcting circuit calculating an error bit count of the read data; and a controller performing a refresh operation, in which the read data stored in one of the memory groups is temporarily stored in the second memory region and is written back the read data to the same memory group, when the error bit count exceeds a first threshold or when the data read count exceeds a second threshold.

Techniques for encryption key destruction for secure data erasure via an external interface or physical key removal are described. Electrical destruction of key material retained in a memory of a storage device renders the device securely erased, even when the device is otherwise inoperable. The memory (e.g. non-volatile, such as flash) stores key material for encrypting/decrypting storage data for the device. An eraser provides power and commands to the memory, even when all or any portion of the device is inoperable. The commands (e.g. erase or write) enable zeroizing or destroying the key material, rendering data encrypted with the destroyed key material inaccessible, and therefore securely erased. Alternatively, the memory is a removable component (e.g. an external security device or smartcard) coupled to the device during storage operation. Removing and physically destroying the memory renders the device securely erased. The device and/or the memory are sealed to enable tamper detection.

There is provided a logical volume management method for storage system. When a logical volume is created on a flash memory drive, a management computer allocates logical volume while flash memory chip border of flash memory drive is taken into account. Specifically, a table for managing a correlation between each parity group and the flash memory chip of the flash memory drive is obtained and the logical volume is allocated in such a manner that a flash memory chip is not shared by a plurality of logical volumes. When complete erasing of logical volume data is performed, the management computer specifies a flash memory chip on which complete data erasing is to be performed, and the storage system completely erases data exclusively on the chip of interest with a use of a function of completely erasing data at a time by chip unit of the flash memory chip (chip erasing).

A memory system includes a nonvolatile semiconductor memory having blocks, the block being data erasing unit; and a controller configured to execute; an update processing for; writing superseding data in a block, the superseding data being treated as valid data; and invalidating superseded data having the same logical address as the superseding data, the superseded data being treated as invalid data; and a compaction processing for; retrieving blocks having invalid data using a management tablet the management table managing blocks in a linked list format for each number of valid data included in the block; selecting a compaction source block having at least one valid data from the retrieved blocks; copying a plurality of valid data included in the compaction source blocks into a compaction target block; invalidating the plurality of valid data in the compaction source blocks; and releasing the compaction source blocks in which all data are invalidated.

A rewritable optical information recording medium including a recording layer composed of an organic dye film is provided, in which recording and erasing information can be performed reversibly by laser light irradiation. A rewritable optical information recording medium including at least one organic dye film which is substantially made of only at least one kind of organic dye compounds as a recording film is provided. The recording and erasure of information are performed by a reversible physical change of the organic dye film substance caused by laser light irradiation. Specifically, data recording is performed by a physical change locally caused by the irradiation of recording laser light, data reproduction is performed by detecting change in intensity of returned light of reproducing laser light having less power than the recording laser light, and data erasure is performed by applying at least once continuous light or pulse light having laser power more than the reproducing laser light and less than the recording laser light. The physical change is a change in shape.

For an optical recording medium having a phase change type recording layer on its a substrate and having as read only area and a writable area in a recording area, a data recording method is provided which records data in the writable area. This data recording method comprises a transfer step of transferring program data recorded in the read only area in a practical form to an external computer, and an execution step (step A10) of automatically executing the program data in the external computer to record data in the writable area, which can facilitate manufacturing and reduce the possible of destruction or falsification of ROM data.

A system for remotely erasing data, a method, a server, and a mobile device thereof, and a computer program product are provided. The method is adapted for the mobile device having an internal storage unit and an external storage unit, wherein a user account of a service website is set up for the mobile device. In the method, a relationship between the user account and the mobile device is recorded in the server. The server receives a data erasing request corresponding to the user account through the service website, and sends a remote control command to the mobile device corresponding to the user account. Then, the mobile device erases data stored in the external storage unit thereof according to the remote control command.

A system is provided to ensure a timely secure data erase by determining whether allocating an additional tape drive would improve secure data erase performance by evaluating a quantity of physical volumes to be secure data erased, a maximum queued threshold, an average time to an erasure deadline and a minimum expiration threshold. An additional tape drive is allocated for the secure data erase process when it is determined that allocating an additional tape drive would improve secure data erase performance.

A method for protecting data completeness of flash storage includes calculating out calibration sum of data to be written in and storing data and said sum in blank region of write in storing zone then writing data with said sum in corresponding position in backup storing zone ( BSZ ), erasing off a block of data in main storing zone ( MSZ ) first and then erasing off a block of data in said position on BSZ, fetching and calibrating data of MSZ and fetching as well as calibrating data stored in said position on BSZ if data in MSZ is damaged, using effective data in BSZ to cover damaged data in MSZ.

A physical group address is allocated to a storage area of a flash memory (11) for each group as units smaller than a block as units of data erasing, and the group includes multiple pages and the page includes multiple columns. When writing data and a logical address of a writing destination are supplied, a CPU (121) writes the data in a column in the group indicated by a writing pointer to associate the supplied logical address with the column. A relationship between the physical group address of the group having this column and the logical group address is stored in a logical/physical conversion table of a RAM (123). Data stored in the block is erased when the number of blocks having no empty block reaches a predetermined number or less.

A control method of a non-volatile memory apparatus, which can execute data writing normally after the next startup even when a process is interrupted because of the occurrences of abnormal conditions such as power shut down during data writing or data erasing is provided. The control method of a non-volatile memory apparatus of the present invention comprises: a first flag writing step of writing a fixed value, which indicates that data is written, on a first flag existing in a redundancy area on a first page of a physical block and indicating whether or not data is written on the first page; and a data writing step of writing data on the physical block, when the data is written on the non-volatile memory consisting of a plurality of physical blocks.

Private data in an EEPROM (14) is erased in a data erasing procedure when pulling out an SIM card (2) from a mobile telephone (1). Before being erased, the private data is encrypted in an encryption procedure and it is transferred and recorded to an external memory (3). The private data encrypted and recorded to the external memory can be reused when the SIM card is used in another mobile telephone. Furthermore, it is possible to prevent the external memory from being left behind when the SIM card is pulled out by interfacing a lock mechanism of a card mounting section (16) with that of a memory mounting section (17).

The invention discloses a method for obliterating data in a solid state disk, which comprises the following steps: data destroying commands are received; the received data destroying commands are dispatched to each layer of a flash memory chip; and each layer of the flash memory chip obliterates the data in the layer according to the data destroying commands. The invention further provides a corresponding device and a system. The invention adopts that the commands for data obliterating operation are obliterated to each layer of the solid state disk, so that data stored in the solid state diskcan be quickly obliterated, thereby ensuring the security of the data stored in the solid state disk.

A storage system includes a RAID adapter, disk array switches, sub-processors, and hard disk drives (HDDs). A disk-related operation is initiated in the RAID adapter. The RAID adapter dispatches a command to a disk array processor (or sub-processor) in an enclosure for the processor to perform the operation on one or more drives. The adapter may dispatch the command to a processor in a single enclosure through a disk array switch or to processors in multiple enclosures through switches in the upstream enclosures. The adapter is then free to perform other functions. The processor commences the specified operation on one or more selected drives, either sequentially one at a time or sequentially more than one (or all) at a time. Upon completion of the operation, the results are transmitted by the processor and received by the adapter. Thus, by offloading the task to the distributed sub-processors, the burden on the RAID adapter is significantly reduced, system bandwidth usage is reduced, and access to other drives within the enclosure (as well as within other enclosures) may be maintained. Tasks which may be offloaded in such a manner include, but are not limited to, drive firmware updating, drive scrubbing and secure data erasure.

The present invention is to propose an data erasing method, a memory apparatus, and a data erasing circuit which are able to reduce the time required to boost the potential of the semiconductor substrate thereby to reduce the time required to erase data. Namely, a memory apparatus having a data erasing circuit that erases stored data by applying an erasing voltage between a semiconductor substrate and a control gate so as to discharge electric charges accumulated in a floating gate is disclosed. In this case, the data erasing circuit boosts a potential of the semiconductor substrate side while placing the control gate into its floating state; and applies an erasing voltage between the semiconductor substrate and the control gate to make the potential of the control gate to a predetermined potential.

A non-volatile semiconductor memory device includes: a cell array having electrically rewritable and non-volatile memory cells arranged to constitute at least one block with a plurality of pages; and a controller for controlling data erase by a page or sub-block with plural and continuous pages in the block, wherein the cell array has an erase control area set therein in which the number of data erase is stored as being expressed by a series of two-value data, the number of “0” data at lower bit side thereof indicating an accumulated value of the number of data erase in a block, and wherein the number of data erase is read out before data erase for a selected page in the block by a check-read operation in which plural pages are simultaneously set at a selected state, and renewed and written into the selected page after data erase.