US Patent 7519830 Secure storage of data

A secure memory system binds an encrypted first data value stored in a memory with a state of the memory by selecting, at random, an address in the memory and mixing a second data value, stored at the address, with a hash value of the first data value to produce a split value. The address, split value and first data value are encrypted and stored in the memory. To detect tampering of the memory, the encrypted address is decrypted and the corresponding value read from the memory and used to recover a hash value from the decrypted split value. The recovered hash value is then compared with the original hash value.