with most open source software that uses device drivers, the user must enable test signing when running Windows Vista x64 and Windows 7 x64 systems. Driverless operation Packaged with FreeOTFE is another program called "FreeOTFE Explorer", which provides a driverless system that allows encrypted disks to be used without administrator rights. This allows FreeOTFE encrypted data to be used on (for example) public computers found in libraries or computer kiosks (interactive kiosks), where administrator rights are unavailable. Unlike FreeOTFE, FreeOTFE Explorer does not provide on-the-fly encryption through a virtual drive. Instead it lets files be stored and extracted from encrypted disk images, in a similar manner as ZIP and RAR archives, by using a Windows Explorer like interface. Algorithms implemented Due to its architecture, FreeOTFE provides great flexibility to the user with its encryption options. Ciphers FreeOTFE implements several ciphers, including: AES Blowfish CAST5 / CAST6 DES / Triple DES MARS RC6 Serpent Twofish It includes all National Institute of Standards and Technology (NIST) Advanced Encryption Standard (AES) finalists, and all ciphers can be used with multiple different keylengths. Cipher modes FreeOTFE originally offered encryption using cipher-block chaining (CBC) with encrypted salt-sector initialization vector (ESSIV), though from v3.00 introduced LRW and also the more secure XTS mode, which supersedes LRW in the IEEE P1619 standard for disk encryption. Hashes As with its cipher options, FreeOTFE offers many different hash algorithms: MD2 MD4 MD5 RIPEMD-128 RIPEMD-160 RIPEMD-224 RIPEMD-320 SHA-1 SHA-224 SHA-256 SHA-384 SHA-512 Tiger Whirlpool See also Disk encryption Disk encryption software On-the-fly encryption Comparison of disk encryption software References External links Cryptographic software Disk encryption Free security software Windows security software Windows Mobile software Portable software Free software