Abstract: A data transfer system comprising a host device and a data transfer device. The host device generates an encryption key based upon information unique to a removable data storage item onto which data are to be stored. The encryption key is then delivered by the host device to the data transfer device. Data to be stored are encrypted by the data transfer device using the encryption key.

Abstract: A data processing apparatus comprises an integrated circuit containing a data processor and a non-volatile store storing at least one security code. A first memory external to the integrated circuit stores data, the data being cryptographically protected in a first format. A second memory external to the integrated circuit is provided for storing data. The apparatus is arranged to transfer data from the first memory via the integrated circuit to the second memory to be accessed by the data processor from the second memory. The integrated circuit is arranged to validate during the transfer the data read from the first memory using a security code stored in the non-volatile store. If the data is validated, cryptographic protection is applied in a second format to the validated data using a security code stored in the non-volatile store. The protected data is stored in the second memory in the second format.

Abstract: A data processing apparatus comprises a monolithic integrated circuit having a data processor, a non-volatile memory storing at least one security code, and at least one interface at the boundary of the integrated circuit via which communication with the data processor can occur. Processing by the data processor of data received at the at least one interface is controlled by the at least one security code.

Abstract: A data transfer device for transferring data to a removable data storage item. The data transfer device receives content data to be stored to the removable data storage item, encrypts the content data using an encryption key, and transforms at least one of predetermined reference data and the encryption key. The data transfer device also encrypts the transformed predetermined reference data using the encryption key or encrypts the predetermined reference data using the transformed encryption key, and then stores the encrypted content data and the encrypted transformed/predetermined reference data to the removable data storage item.

Abstract: An authenticated encryption method and apparatus are described in which plaintext data is encrypted, using a secret key, to form ciphertext data. A message authentication code, MAC, is also formed in dependence on a combination of the ciphertext data and data characteristic of the plaintext data. The ciphertext data and the MAC are then output, for example, for storage to a storage medium. In a preferred embodiment a block cipher operating in GCM mode is adapted to cause the stored message authentication code to be dependent on the plaintext data.

Abstract: Data are written to plural parallel data tracks of a data storage medium by arranging a data stream into plural streams of data sets. Each stream of data sets is allocated to a corresponding respective group of parallel data tracks. A plurality of the data sets are written to the plural data track groups, such that in each data stream, each data set commences at substantially the same position along a length of the linear data storage medium, as a data set of another of the streams.

Abstract: A data reader is arranged to read data from a data-holding medium, said data being arranged into a plurality of data items each containing user data and non-user data, with said non-user data including one or more synchronisation fields. The data reader has a read head for reading a channel of said data-holding medium to generate a data signal comprising said data items, and processing circuitry arranged to receive and process said data signals to detect synchronisation fields, including qualifying the detection of the synchronisation fields to tolerate one or more errors in those synchronisation fields. This means that the synchronisation fields can be detected more reliably, so that more of the user data is recovered.

Abstract: A linear tape data storage device comprises a read head and a write head; a tape transport mechanism for transporting the linear tape data storage medium across the read head and the write head, the device being operated according to a predefined tape format; a DRAM buffer memory for storing data received during a write or a read operation; and error protection means configured to protect said data from soft errors generated by said buffer memory wherein the protection means comprises means for checking parity generated within the tape format itself. In the preferred embodiment the tape format used is the Linear Tape Open (LTO) format.

Abstract: A data reader is arranged to read data comprising user data 30 and non-user data 32, 34 written across at least two channels of a data-holding medium 10, said data being arranged into a plurality of data items 26 each containing user data and non-user data, with said non-user data holding information relating to said user data, including write pass number information, and data items written across the said channels at the same time being identified as a set of data items, said data reader holding a current write pass number and having a read head 12 for reading a respective said channel of said data-holding medium 10 to generate a data signal comprising said data items, and processing circuitry 258, 280 arranged to receive and process said data signals of a set of data items, including processing said write pass number information of each of said data items in said set, and causing updating of said current write pass number held by said data reader on the basis of the write pass number information of said dat

Abstract: Data from a host computer is buffered, transferred to a logical formatter, compressed and converted to a format suitable for storage on a magnetic tape before being arranged and written sequentially into a main buffer where parity bytes are added as each row of a dataset is written. A physical formatter takes the data sequentially from the main buffer and writes them as codeword quadsets in plural tape tracks. A determination of whether each codeword quadset is acceptably recorded is made by evaluating each codeword quadset for header and codeword quadset pair errors and combining the evaluations.

Abstract: There is disclosed a method of accurately locating an append point along a length of linear tape data storage medium, comprising entering a search mode searching for an absolute code word quad set number, and having found the absolute code word quad set number, entering an interrupt mode for control of tape transport, followed by a write mode to write data at a data set containing the absolute code word quad set number.

Abstract: A data reader reads a medium holding user and non-user data that holds information relating to the user data. The reader has a read head that generates a data signal comprising user and non-user data. The user data is arranged into plural sets interspersed with the non-user data that identifies the user data within the sets. Processing circuitry receives and processes the data signal and obtains the user data from the data signal by using the non-user data to identify the user data within the data signal. The data reader is particularly suitable in situations having re-writes and overwrites.

Abstract: Data are written to plural parallel data tracks of a data storage medium by arranging a data stream into plural streams of data sets. Each stream of data sets is allocated to a corresponding respective group of parallel data tracks. A plurality of the data sets are written to the plural data track groups, such that in each data stream, each data set commences at substantially the same position along a length of the linear data storage medium, as a data set of another of the streams.

Abstract: A data reader is arranged to read data comprising user data and non-user data written across at least two channels of a data-holding medium, the data being arranged into a plurality of data items each containing user data and non-user data, with the non-user data holding information relating to the user data, including a header with information relating to the user data and header error detection information, and data items written across the channels at the same time being identified as a set of data items.

Abstract: A data reader is arranged to read data comprising user data 30 and non-user data 32, 34 written across at least two channels of a data-holding medium 10, said data being arranged into a plurality of data items 26 each containing user data and non-user data, with said non-user data holding information relating to said user data, said data reader having a read head 12 for reading a respective said channel of said data-holding medium 10 to generate a data signal 14 comprising said data items, and processing circuitry 250 arranged to receive and process said data signals to identify a set CCPset1 of said data items written at the same time onto different said channels. Identifying a set of data items written at the same time gives rise to the possibility of correcting header information for the data items in a set.

Abstract: A method for recovering user data from a host device stored on a data storage medium where a said data may become corrupted during a read operation comprises: performing a read operation to read at least one encoded data fragment of said plurality of encoded data fragments from said data storage medium; storing status data indicating whether said at least one data fragment was correctly read; writing said read at least one data fragment to a buffer memory; attempting to decode said at least one encoded data fragment in said buffer memory wherein if said attempted decoding is unsuccessful then said method further comprises the steps of: re-reading incorrectly read encoded data fragments from said data storage medium; and attempting to decode said encoded data fragments located in said buffer memory.

Abstract: A linear tape data storage device comprises a read head and a write head; a tape transport mechanism for transporting the linear tape data storage medium across the read head and the write head, the device being operated according to a predefined tape format; a DRAM buffer memory for storing data received during a write or a read operation; and error protection means configured to protect said data from soft errors generated by said buffer memory wherein the protection means comprises means for checking parity generated within the tape format itself. In the preferred embodiment the tape format used is the Linear Tape Open (LTO) format.

Abstract: A data reader is arranged to read data from a data-holding medium, said data being arranged into a plurality of data items each containing user data and non-user data, with said non-user data including one or more synchronisation fields. The data reader has a read head for reading a channel of said data-holding medium to generate a data signal comprising said data items, and processing circuitry arranged to receive and process said data signals to detect synchronisation fields, including qualifying the detection of the synchronisation fields to tolerate one or more errors in those synchronisation fields. This means that the synchronisation fields can be detected more reliably, so that more of the user data is recovered.

Abstract: A data reader is arranged to read data comprising user data and non-user data written across at least two channels of a data-holding medium, the data being arranged into a plurality of data items each containing user data and non-user data, with the non-user data holding information relating to the user data, including a header with information relating to the user data and header error detection information, and data items written across the channels at the same time being identified as a set of data items.

Abstract: A data reader is arranged to read data comprising user data 30 and non-user data 32, 34 written across at least two channels of a data-holding medium 10, said data being arranged into a plurality of data items 26 each containing user data and non-user data, with said non-user data holding information relating to said user data, said data reader having a read head 12 for reading a respective said channel of said data-holding medium 10 to generate a data signal 14 comprising said data items, and processing circuitry 250 arranged to receive and process said data signals to identify a set CCPset1 of said data items written at the same time onto different said channels. Identifying a set of data items written at the same time gives rise to the possibility of correcting header information for the data items in a set.