the reason behind the announcement arose throughout the tech community. Shortly after the end of life announcement of TrueCrypt, Gibson Research Corporation posted an announcement titled "Yes... TrueCrypt is still safe to use" and a Final Release Repository to host the last official non-crippled version 7.1a of TrueCrypt. They no longer host the final release repository as of 2022. Truecrypt.org has been excluded from the Internet Archive Wayback Machine. Their exclusion policy says they exclude pages at site owner request. Operating systems TrueCrypt supports Windows, OS X and Linux operating systems. Both 32-bit and 64-bit versions of these operating systems are supported, except for Windows IA-64 (not supported) and Mac OS X 10.6 Snow Leopard (runs as a 32-bit process). The version for Windows 7, Windows Vista, and Windows XP can encrypt the boot partition or entire boot drive. Independent implementations There is an independent, compatible implementation, tcplay, for DragonFly BSD and Linux. The Dm-crypt module included in default Linux kernel supports a TrueCrypt target called "tcw" since Linux version 3.13. Encryption scheme Algorithms Individual ciphers supported by TrueCrypt are AES, Serpent, and Twofish. Additionally, five different combinations of cascaded algorithms are available: AES-Twofish, AES-Twofish-Serpent, Serpent-AES, Serpent-Twofish-AES and Twofish-Serpent. The cryptographic hash functions available for use in TrueCrypt are RIPEMD-160, SHA-512, and Whirlpool. Modes of operation TrueCrypt currently uses the XTS mode of operation. Prior to this, TrueCrypt used LRW mode in versions 4.1 through 4.3a, and CBC mode in versions 4.0 and earlier. XTS mode is thought to be more secure than LRW mode, which in turn is more secure than CBC mode. Although new volumes can only be created in XTS mode, TrueCrypt is backward compatible with older volumes using LRW mode and CBC mode. Later versions produce a security warning when mounting CBC mode volumes and recommend that they be replaced with new volumes in XTS mode. Keys The header key and the secondary header key (XTS mode) are generated using PBKDF2 with a 512-bit salt and 1000 or 2000 iterations, depending on the underlying hash function used. Plausible deniability TrueCrypt supports a concept called plausible deniability, by allowing a single "hidden volume" to be created within another volume. In addition, the Windows versions of TrueCrypt have the ability to create and run a hidden encrypted operating system whose existence may be denied. The TrueCrypt documentation lists many ways in which TrueCrypt's hidden volume deniability features may