XTS mode
A block cipher mode for disk encryption that tweaks each block by its sector number and position, instead of using an IV.
XTS builds on Phillip Rogaway's XEX from 2004 and was standardised for storage in IEEE 1619-2007 and in NIST SP 800-38E. Each 16-byte block is encrypted with AES after being XORed with a tweak derived from the sector number and the block's position. Two identical blocks at different positions therefore produce different ciphertext, and ECB's pattern leakage is avoided.
XTS is not an authenticated mode. Anyone who can write to the disk can alter the data without anyone noticing. Sectors whose length is not a multiple of 16 bytes are handled with ciphertext stealing. Tools such as dm-crypt and VeraCrypt have made XTS routine, which is exactly why it should be used with a clear idea of what it does not protect against.