1ABOUT 2-- 3Bcrypt is a cross platform file encryption utility. Encrypted files are 4portable across all supported operating systems and processors. Passphrases 5are between 8 and 56 characters and are hashed internally to a 448 bit 6key. However, all characters supplied are significant. The stronger your 7passphrase, the more secure your data. 8 9Bcrypt uses the blowfish encryption algorithm published by Bruce Schneier 10in 1993. More information on the algorithm can be found at: 11 http://www.counterpane.com/blowfish.html 12 13Specifically, bcrypt uses Paul Kocher's implementation of the algorithm. 14The source distributed with bcrypt has been slightly altered from the 15original. Original source code can be obtained from: 16 http://www.counterpane.com/bfsh-koc.zip 17 18SUPPORTED PLATFORMS 19-- 20Bcrypt has been successfully tested on the following platforms: 21 22 x86 23 FreeBSD, OpenBSD, Linux, Cygwin, Win32 24 Sparc R220 25 Solaris 2.7, 2.8 26 Sparc Ultra60 27 Linux 2.4 28 Alpha 29 Linux 2.4 30 PPC G4 31 MacOS X 10.1 SERVER 32 PPC RS/6000 33 Linux 2.4 34 35No other operating systems have been tested, but most should work with 36minimal modifications. If you get bcrypt to compile without errors on any 37other platform / architecture, I'd like to know about it. If patches are 38necessary to get bcrypt work on your OS, I will try to incorporate them 39into the main distribution. 40 41If you have a machine not listed above that is incapable of compiling 42bcrypt and are willing to give me access to the machine, I will make an 43attempt to port it to your OS. 44 45SYSTEM REQUIREMENTS 46-- 47zlib - http://www.gzip.org/zlib/ 48 49INSTALLATION 50-- 51If you're so inclined, edit config.h and change the defaults to whatever 52you think is appropriate for your needs. If you choose not to have 53bcrypt remove input files after processing, or set SECUREDELETE to 0, 54you are likely to have data on your hard drive that can be recovered 55even after deletion. 56 57All of these options can be set on the command line as well. When you're 58satisfied with the default settings, simply type: 59 make 60then su and type: 61 make install 62 63It would be wise to test the installation on a few unimportant files 64before encrypting anything you value and removing the only copy. 65 66USAGE 67-- 68 bcrypt [-orc][-sN] file ... 69 70Encrypted files will be saved with an extension of .bfe. Any files ending 71in .bfe will be assumed to be encrypted with bcrypt and will attempt to 72decrypt them. Any other input files will be encrypted. If more than one 73type of file is given, bcrypt will process all files which are the same as 74the first filetype given. 75 76By default, bcrypt will compress input files before encryption, remove 77input files after they are processed (assuming they are processed 78successfully) and overwrite input files with random data to prevent data 79recovery. 80 81Passphrases may be between 8 and 56 characters. Regardless of the 82passphrase size, the key is hashed internally to 448 bits - the largest 83keysize supported by the blowfish algorithm. However, it is still wise to 84use a strong passphrase. 85 86OPTIONS 87 -o print output to standard out. Implies -r. 88 89 -c DO NOT compress files before encryption. 90 91 -r DO NOT remove input files after processing 92 93 -sN How many times to overwrite input files with random 94 data before processing. The default number of 95 overwrites is 3. Use -s0 to disable this feature. 96 No effect if -r is supplied. 97 98The options o,c and r each have the opposite effects if the appropriate 99settings are altered from the default in config.h. To determine what 100effect each of these have, run bcrypt without any options. 101 102Encrypted files should be compatible between most systems. Binary 103compatibility has been tested for all systems listed above. 104 105/* ==================================================================== 106 * Copyright (c) 2002 Johnny Shelley. All rights reserved. 107 * 108 * Bcrypt is licensed under the BSD software license. See the file 109 * called 'LICENSE' that you should have received with this software 110 * for details 111 * ==================================================================== 112 */ 113