Abstract: A data storage device having mediametric properties used as a source of data for cryptoprocessing keys. A memory array is formed by a plurality of memory cells, each cell containing a level of trapped charges that are difficult or impossible to set to a specific value, but which may be read relatively precisely. The levels of trapped charges are read from selected cells. Data relating to the level of the trapped charges is used to produce the cryptoprocessing keys. In addition, data relating to the charge levels in a memory array is used in generation of random numbers. When a random number is desired, data is written to selected cells of the memory array in order to establish random charge levels in the cells. The data is then read from the selected cells and processed to yield a random number.

Abstract: Methods and apparatus for increasing the density of data storage on a magnetic medium by using variations in positioning of magnetic transitions to encode bits. Conventionally encoded bits are written to the medium as sequences of magnetic transitions according to an encoding standard. Additional bits are encoded on the medium as deviations from a nominal position of magnetic transitions separating conventionally encoded bits. The deviation from the nominal position is within an allowable range of tolerance for the standard followed in encoding the conventionally encoded bits. In order to prevent accumulation of error, additional bits are only encoded in transitions separating a pair of conventionally encoded bits. The first and last transitions of the pair do not have additional bits encoded as deviations of transition locations. This technique allows the encoding of one additional bit for every two conventionally encoded bits.

Abstract: A method and apparatus for authenticating data stored in semiconductor memory cells. A reference fingerprint representing trapped charges in memory cells of a semiconductor device is created. Data is written to selected cells of the semiconductor device. After the data is written, the levels of trapped charges in the selected cells is determined by performing a series of read operations using progressively greater read thresholds. The level of trapped charges in a memory cell is identified by noting the voltage threshold at which the memory cell is read as a digital “1”. Once the levels of trapped charges of the memory cells are identified, a reference fingerprint is created to identify the semiconductor device. The reference fingerprint may be stored on the semiconductor device or on an external device.

Abstract: Methods and apparatus for increasing the density of data storage on a magnetic medium by using variations in positioning of magnetic transitions to encode bits. Conventionally encoded bits are written to the medium as sequences of magnetic transitions according to an encoding standard. Additional bits are encoded on the medium as deviations from a nominal position of magnetic transitions separating conventionally encoded bits. The deviation from the nominal position is within an allowable range of tolerance for the standard followed in encoding the conventionally encoded bits. In order to prevent accumulation of error, additional bits are only encoded in transitions separating a pair of conventionally encoded bits. The first and last transitions of the pair do not have additional bits encoded as deviations of transition locations. This technique allows the encoding of one additional bit for every two conventionally encoded bits.

Abstract: Methods and apparatus for increasing the density of data storage on a magnetic medium by using variations in positioning of magnetic transitions to encode bits. Conventionally encoded bits are written to the medium as sequences of magnetic transitions according to an encoding standard. Additional bits are encoded on the medium as deviations from a nominal position of magnetic transitions separating conventionally encoded bits. The deviation from the nominal position is within an allowable range of tolerance for the standard followed in encoding the conventionally encoded bits. In order to prevent accumulation of error, additional bits are only encoded in transitions separating a pair of conventionally encoded bits. The first and last transitions of the pair do not have additional bits encoded as deviations of transition locations. This technique allows the encoding of one additional bit for every two conventionally encoded bits.