سيستم فايل امن مبتني بر پردازنده هاي گرافيكي

چكيده انگليسي :

GPU based Secure File System Mohsen Koohi m koohi@ec iut ac ir 12 February 2012 Department of Electrical and Computer Engineering Isfahan University of Technology Isfahan 8415683111 IranDegree M Sc in Computer Architecture Language FarsiSupervisor Prof Mohammah Ali Montazerimontazer@ec iut ac irAbstractBoosting of processors power by increasing the number of cores necessitates operating systems that use allthe cores carry out jobs in parallel The presence of GPUs with a lot of cores enables OS to send processes tothem and therefore to increase the performance of OS On the other hand for many years users attended thesecurity of their information and because of vast amount of computations needed for encryption we can useGPUs for data encryption In this thesis we design and implement a secure file system that uses GeneralPurpose Graphical Processing Units GPGPUs GPGPU based Secure File System GSFS provides integrityand confidentiality of data This file system makes data inodes accessible for different users and also enablesusers to expand shrink the access level in each point of the tree structure of the inodes Using these twotechniques GSFS provides information sharing for users GSFS uses Crust key revocation method foreffective user revocation Crust requires only d keys to store for revoking of n md and also it can derive keyswith maximum m usage of hash function GSFS also uses cryptographic links of Cryptree to decrease theusage of public key encryption Cryptographic links encrypts the key of lower level inodes with parent inodekey and in this way we don t need public key encryption algorithms to encrypt decrypt the child inodes keys GSFS uses Galois Counter Mode GCM for regular secure inodes integrity and confidentiality GCM is acounter block cipher that provides integrity as well as confidentiality GCM uses galois hash for calculatingthe hash of each block For each block of secure regular inodes GSFS stores the VIA values Version of crustkey the Initiation Vector IV and the Authenticated Tag AT GSFS uses a merkel tree for reading andwriting the VIAs pages quickly In current version GSFS can store up to 64GB secure regular inode GSFSalso uses another merkel tree to store and resotre the directory entries dentries of each secure directoryinode GSFS uses root user public key to make file system integrated and uses users public keys forconfidentiality and therefore it diffrentiates between integrity and confidentiality GSFS uses root userprivate key to sign the digest of super block with a timestamp This value is shown to the root user at the startand at the end of mounting the GSFS and in this way the ability of replay attacks is diminished GSFS isimplemented as a linux kernel module and in current version it uses one OpenCL user level program toencrypt decrypt data in parallel with CPU and GPU Our examinations show GSFS provides these propertieswith no less rate in comparison with ext3 for insecure inodes but GSFS rate is less than eCryptfs rate becauseof its security algorithms Also using GPU in our OpenCL program doubles the rate of GSFS in comparisonwith using CPU Using one independent process for our parallel encryption decreases our performancebecause of the cost of context switch and therefore we need to use OpenCL in kernel in future versions toimprove perfromance of GSFS Keywords Secure File System GPGPU Parallel Processing OpenCL Operating System Linux GCM RSA

كوهي، محسن

سيستم فايل امن مبتني بر پردازنده هاي گرافيكي

همه منظوره , پردازش موازي , سيستم عامل , لينوكس , open CL