What is XTS encryption?
XTS is the newest block cipher mode and is the cipher mode used by DataTraveler 4000G2 and DataTraveler Vault Privacy 3.0. It was designed as a stronger alternative to other available block cipher modes such as CBC.
What is XTS-AES mode of operation is used for?
The XTS-AES mode is designed for encrypting data stored on hard disks where there is not additional space for an integrity field. Given this lack of space for an integrity field, XTS-AES builds on the security of AES by protecting the storage device from many dictionary and copy/paste attacks.
Is BitLocker AES 256?
Is it configurable? BitLocker uses Advanced Encryption Standard (AES) as its encryption algorithm with configurable key lengths of 128 bits or 256 bits. The default encryption setting is AES-128, but the options are configurable by using Group Policy.
Is AES XTS secure?
At the end, this paper restates and expands the proof sketch of Liskov and Minematsu that XTS-AES is indeed CCA secure as a tweakable cipher when cipher- text stealing is used.
What is the size of XTS-AES key?
While AES key length is 256 bits, XTS+AES pair uses a 256+128 = 384 bits key.
What is the purpose of XTS in disk encryption?
XTS Mode is a block cipher mode of operation intended for use on storage devices to encrypt disk sectors. XTS mode was originally specified by the IEEE in P1619, and NIST standardized it in SP800-38E .
What kind of ciphertext is used in XTS?
XTS builds on top of XEX designed by Phillip Rogaway and extends this by a tweak value and ciphertext stealing. The mode defined by IEEE uses an AES cipher, in fact AES is used twice. Simplified (without i and alpha), the tweak value is encrypted, then XORed with the plaintext block.
What are the two AES keys used in XTS?
XTS uses two AES keys. One key is used to perform the AES block encryption; the other is used to encrypt what is known as a “Tweak Value.” This encrypted tweak is further modified with a Galois polynomial function (GF) and XOR with both the plain text and the cipher text of each block.
What do you need to know about XTS mode?
The mode does not require a multiple of a block size or padding, which means there is no cipher text expansion. XTS does require at least 16 bytes of plain text. The 16-byte requirement comes from the fact the mode steals cipher text from a previous encrypted block when there are tail bytes present.