Improving data integrity and performance of Cryptographic Structured Log File Systems

Abstract

Modern File systems like CLFS (Cryptographic Log Structured File System)are aimed to provide security and confidentiality. Current deployments of such FileSystems do not currently ensure data integrity of the encrypted data that is stored ondisk. Due to Kernel bugs, racing conditions and arbitrary dead-locks, CLFS data onthe disc can be damaged, also there is always the possibility that system users canmodify the encrypted data. Our study aims toward ensuring data integrity on CLFSwithout compromising on overall performance. This paper considers the standardmethods using file metadata check-summing in CLFS with the main goal toovercome one of its major limitations, low performance of File-System checksumming.CLFS matches our performance expectations, as it performs close enoughto non-cryptographic file systems. To improve the performance of the checksummingprocess we try to study and examine various design choices and proposean in-kernel database for storage and reduction of check-sum verification once in Nread requests.