Encrypted flash-based data storage system with confidentiality mode

摘要

Raw or unencrypted data is encrypted using a standard encryption algorithm and stored in a Flash memory array. The raw or unencrypted data may be pre-processed before it is encrypted. Pre-processing may include data scrambling, pre-encryption data mixing, or both. Data scrambling may involve an invertible transformation. The scrambled data may then be used to seed a sequence generator. Each output from the sequence generator may be processed using a bit-by-bit Exclusive Or (XOR) operation to impart random or pseudorandom statistical properties. Pre-encryption data mixing may combine the scrambled (or unscrambled) data with information that is unique to each chunk of data, as well as with a user-supplied secret key. This helps ensure that identical raw data chunks are not stored as identical encrypted data chunks in the Flash memory array.

主权项

1. A method of preserving confidentiality in a Flash-based storage system, comprising:
receiving data from an external host to be written to the Flash-based storage system; writing the data to a plurality of Flash memory chips in the Flash-based storage system, the data being written to the Flash memory chips in the form of page stripes, each page stripe comprising a number of data pages, each data page of a page stripe being written to a different Flash memory chip from other data pages of the page stripe; for data having identical data pages, preserving a confidentiality of the data, the confidentiality preventing the identical data pages from being correlated, the preserving comprising mixing the data pages of the page stripe being written to the Flash memory chips, the mixing comprising performing a mathematical and/or logical operation on the data pages so that identical data pages appear different from one another after encryption; and encrypting the mixed data pages of the page stripe being written to the Flash memory chips.