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Rijndael was created because of the shortcomings of DES and triple-DES.  After a thorough examination of submitted encryption algorithm proposals.  AES resembles DES in the sense that it also uses combinations of transpositions and substitutions; AES, however, is much more flexible with respect to keys, which may be 256 or more bit.

Rijndael works by generating 10 128-bit keys from the 128-bit key which are stored in 4 x 4 tables. The plain text is also divided into 4 x 4 tables (each in 128-bit chunks). Each of the 128-bit plain text pieces is processed in a 10-round process (10 rounds on 128-bit keys, 11 on 192, 13 on 256).

The code will be generated after the 10th round. The rows of the matrices are now sorted cyclically. While the columns are exchanged by matrix multiplication via a Galois field (GF) (2 8). The security of this encryption method increases when Rijndael is performed several times with different round keys. Brute- Force attack can be prevented by Rijndael because the key length can exceed 128 bits.

Reference:

John KelseyStefan LucksBruce Schneier, Mike Stay, David Wagner, and Doug Whiting, Improved Cryptanalysis of Rijndael, Fast Software Encryption, 2000 pp213–230  “Academic: Improved Cryptanalysis of Rijndael – Schneier on Security”  Archived from the original on 2007-02-23. Retrieved 2007-03-06.

The Rijndael algorithm for the AES encryption was designed following the three principles of resisting all known possible attacks, speed and compactness of the source code and to make the design as simple as possible. Its encryption process uses a set of round keys on a ray of data alongside other operations. The arrays hold exactly one block of data referred to as state array that needs to be encrypted (Nivetha, 2017). Data handling takes place in 128-bit blocks where the blocks can mirror the different key sizes. The steps involved in the AES encryption process are as follows. First, the round keys are derived from the cipher key. Secondly, the state array is initialized with the block data which is mainly the plain text to be encrypted. This is followed by adding the initial round key to the starting state array. The next step involves the manipulation of the data in about nine rounds. Then it has to be ensured that the tenth round of the data manipulation is performed. Lastly, the final state array is then copied out. This becomes the encrypted data or ciphertext. The nine and the tenth rounds of manipulation of the data are done to ensure that the tenth manipulation involves a slightly different method of manipulation from the others. This then completes the process of AES encryption.

Reference

Nivetha, K. (2017). Steps in the AES Encryption Process:: Appendix A. Overview of the AES Block Cipher :: Appendixes :: 802.11 security. wi-fi protected access and 802.11i :: Networking :: eTutorials.org. Retrieved 5 March 2020, from http://etutorials.org/Networking/802.11+security.+wi-fi+protected+access+and+802.11i/Appendixes/Appendix+A.+Overview+of+the+AES+Block+Cipher/Steps+in+the+AES+Encryption+Process/

There are many encryption techniques are used to encrypt the secured information.It Is very dangerous that transfer the secured information from one place to another without any security.till now many encryption methods are used but the truth is that almost all the techniques are easy to decode.the problem is about in cryptographic language is that once the cypher text found then rest of the work is easy to decode all the text is easy.so nowadays another encryption technique is used to send the secured information.the method is Rijndael algorithm.

The U.S.National Bureau of standards has created a complicated encryption standard it is called as Data encryption standards (DES).This method provides unlimited ways to encrypt the secured information.and this encryption method is replaced by Rijndael Algorithm.the name Rijndael is given by John Deamon and Vincent Rijmen these are the tow Belgian cryptologist experts has derived this algorithm this uses the key of 128,192 and 256 bits which

provides a high security from many attacks like brute force attack. and another good thing about this method is that this algorithm works 4 times faster than the DES algorithm.this algorithm transfers the data very securely with 128,192 and 256 bits.

Deutschland. (n.d.). How does the encryption algorithm Rijndael work? (Also known by the abbreviation AES). Retrieved from

Liu, W., Sun, K., & Zhu, C. (2016). A fast image encryption algorithm based on chaotic map. Optics and Lasers in Engineering84, 26-36.

The Rijdael algorithm is used with AES encryption method. Encryption is accomplished with a fixed block size of 128, 192, or 256-bit key, which provides guaranteed increased security against brute-force attacks. Brute-force attacks were associated with the DES standard and rendered it somewhat ineffective. In addition to better security, AES worked faster that the DES encryption method. AES is the world standard in encryption.

The Rijdael algorithm works by generating 10 128 bit keys and stores them in symmetrical tables. Plaintext is also divided into symmetrical tables. Each of the 128-bit plaintext pieces is processed in a 10-round process (10 rounds on 128-bit keys, 11 on 192, 13 on 256). Code is generated after 10 rounds. Bytes are substituted in D-box and the rows are sorted in cycles. An XOR link is then applied to each subkey. Security is increased with multiple rounds of different keys.

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There is much more rich data available in the MFT, but what is the one thing provided by the MFT and not the FAT that makes it difficult to find small files is that if a folder is small enough to fit in the MFT record then the NTFS reads the entire folder when it reads its MFT record so the small files are entirely contained within the MFT record. This makes the reading small files difficult in MFT. FAT  proposed how to store larger file up to 256 GiB  bytes on slightly modified and otherwise backward-compatible. This can impose a risk because FAT32 implementations not aware of this extension may truncate or delete files exceeding the normal FAT32 file size limit.

Some challenges in MFT are:

• We should never use MFT over small size volumes like less than 400 MB because the amount of overhead involved in NTFS in very high.
• There is no encryption system and anyone can view the data utilizing some means such as low level disk editing utility.
• Not formatting available for floppy disks.

References:

Rashid, Fahmida Y. (20 June 2017). “The Best Secure Managed File Sharing Services”. PCMag UK. Archived from the original on 13 May 2019. Retrieved 20 May 2019.

“A brief introduction to FAT (File Allocation Table) formats”  www.wizcode.com . Archived from  the original  on September 25, 2015. Retrieved September 24, 2015.

The MFT helps in allocation for a particular amount of the space for the concerned file records which are being used for storing the attributes of the file. Here, the small files as well as directories which can be stored for in the MFT records. It is the NTFS file access is considered as fast one with respect to the FAT. Also, it is the place where the information about any of the file. as well as the directory where the NTFS volume is getting stored. The file allocation is bitmap.

Whereas the FAT is the computer file system architecture where the OS maintains the hard disk which provides the Map of the clusters where the file has been stored in FAT 16 or the FAT 32. The file allocation is a linked list.

The challenge is that linked list is less in performance when bitmap is considered.

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NTFS vs. FAT

A file system is a technique of organizing and storing the data on the drive, it also specifies what type of attributes can be attached to a file such as filenames, permission, other attributes.

When you save a file to the hard disk, the file is saved in clusters. A cluster is an individual unit of storage on the hard disk The hard disk cannot work with partial clusters. Therefore, even a 1 byte file occupies an entire cluster. The amount of space that is wasted in such a situation is determined by the cluster size.  The smaller the cluster size, the less wasted space you have when a partial cluster is used. The cluster size must change with the size of the hard disk.

FAT and NTFS are the files systems used in an operating system. There are three versions of FAT which are, FAT12, FAT16 and FAT32 and they differ in the size of the file and structure on the disk. The FAT file system was first used in MS-DOS where the maximum size of the hard drive can be 32 MB consisting sectors of 512 K partitions (Anonymous, 2018). NTFS is the successor of the FAT 32 which is used in newer versions of operating systems such as Windows NT and 2000 and its later versions while FAT32 is the oldest version of the file systems and used in earlier versions of the operating system such as DOS and Windows version before XP (Anonymous, 2018).

The prior difference between FAT and NTFS is that NTFS file system can trace the changes committed in the system with the help of maintaining the journal. It uses a transaction-logging system that makes it much less susceptible to failure than FAT. Additionally, NTFS supports large file and volume size and provide efficient data organization. NTFS is also designed to offer file system-level security. Each file on the partition may be assigned attributes that control who may access the file and what they may do with it (read, read/write, etc.) Because of the security that is built into NTFS, only Windows NT and Windows 2000 can access an NTFS partition.

In conclusion, the NTFS file system is newer technology which provides more features as compared to FAT32 such as reliability, security and access control, storage efficiency, enhanced size and name of the file. Even though, the FAT32 is still in use because of its compatibility.

Volumes with a large number of relatively small files exhaust the MFT zone space first.

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