Abstract: An integrated circuit with a secure memory location is comprised of a memory and a circuit which receives a twenty-four bit command word. At least one location in the memory stores at least one secure subkey. The circuit responds to the command word with an access to a secure memory location if and only if the command word specifies a starting address of a secure subkey and the command word is transmitted in both true and bit complimented form. Each subkey is made up of a 64-bit ID field, a 64-bit password field and a 384 bit secured data field.

Abstract: A low-power secure memory in which block move operations are performed without extensive write operations. A translation register holds a set of pointers which affect the address decoding. By changing the values in this special register, the logical addresses of the physical SRAM cell locations in the memory array (or arrays) to be changed without performing any write operations in the array. This avoids the charge consumption which would otherwise be required for charging and discharging bitlines as the memory cells are read and written to.The chip of the preferred embodiment includes a scratchpad memory as well as multiple secure memories (multiple "subkeys"). The Move Block command can transfer a block of data from the Scratch Pad directly into the corresponding block location within a secure subkey, or can replace the entire contents of a secure subkey partition (including the ID and Password fields) with the entire contents of the Scratch Pad.

Abstract: An electronic key which includes a pseudo-random number generator. If the correct password is received, the contents of a secure memory will be outputted by the electronic key. However, if an incorrect password is received, that password will be used as a seed value for the pseudo-random number generator, and the resulting value will be outputted.Thus, if a copier exercises the key through all possible passwords, the incorrect passwords, as well as the correct password, will result in the same output data every time it is tried.