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Comprehensive Algorithm Support

  • Jacksum supports 471 algorithms including
  • National standards of cryptographic hash functions: SHA-1, SHA-[224,256,384,512], SHA-512/[224,256] (USA, NIST FIPS 180-4); SHA3-[224,256,384,512], SHAKE[128,256] (USA (NIST FIPS 202); GOST, GOST Crypto-Pro (Russia, GOST R 34.11-94); Streebog-[256,512] (Russia, GOST R 34.11-2012); SM3 (China); Kupyna[256,384,512] (Ukraine, DSTU 7564:2014); LSH-256-[224,256], LSH-512-[224,256,384,512] (South Korea, KS X 3262); HAS-160 (KISA, South Korea)
  • All 5 candidates from round 3 the NIST SHA-3 competition (2007-2012): BLAKE-[224,256,348,512], Groestl-[224,256,384,512], JH[224,256,284,512], Keccak[224,256,384,512], Skein-256-[8..256], Skein-512-[8..512], Skein-1024-[8..1024]
  • 3 candidates from round 2 of the NIST SHA-3 competition (2007-2012): ECHO-[224,256,348,512], Fugue-[224,256,348,512], Luffa-[224,256,348,512]
  • Proposals from the 2005 NIST workshops before the SHA-3 competition: DHA-256, FORK-256, VSH-1024
  • International accepted, modern strong cryptographic hash functions: BLAKE2s-[8..256], BLAKE2b-[8..512], BLAKE3, ed2k, HAVAL-[160,192,224,256]-[3,4,5], RadioGatun[32,64], RIPEMD[160,256,320], Tiger2, Whirlpool
  • eXtendable Output Functions (XOF) as cryptographic hash functions with a fixed length: SHAKE128, SHAKE256, KangarooTwelve, MarsupilamiFourteen
  • Broken cryptographic hash functions for education and backwards compatibility purposes: HAVAL-128-[3,4,5], MD2, MD4, MD5, MDC2, PANAMA, RIPEMD-128, SHA-0, SHA-1, Tiger, Tiger/128, Tiger/160, Whirpool-0, Whirlpool-T
  • Checksums that can be found in software products and operating systems: Adler-32, cksum (Minix), cksum (Unix), ELF (Unix), Fletcher's Checksum, FNV-0_[32,64,128,256,512,1024], FNV-1_[32,64,128,256,512,1024], FNV-1a_[32,64,128,256,512,1024], joaat, sum (BSD Unix), sum (Minix), sum (System V Unix), sum [8,16,24,32,40,48,56], xor8, XXH32
  • CRCs that are being used in many software products and protocols: CRC-8 (FLAC), CRC-16 (LHA/ARC), CRC-16 (Minix), FCS-16, CRC-24 (OpenPGP), CRC-32 (FCS-32), CRC-32 (MPEG-2), CRC-32 (bzip2), CRC-32 (FDDI), CRC-32 (UBICRC32), CRC-32 (PHP's crc32), CRC-64 (ISO 3309), CRC-64 (ECMA-182), CRC-64 (prog lang GO, const ISO), CRC-64 (.xz and prog lang GO, const ECMA)
Multi-Core/Multi Processor Support
  • Process hash calculation and hash verification simultaneously in multi-processor/multi core environments
  • Works well if you have many cores, and many hundreds, thousands or millions of files to process and/or
  • Works well if you have selected more than one algorithm

Algorithm Selection

  • Select one, many, or all algorithms for hash calculation and verification
  • Select algorithms manually, filter them by name or message digest width
  • Use any of the predefined CRC or customize your own CRC, because Jacksum supports the "Rocksoft (tm) Model CRC Algorithm", and an extended model of it
  • Algorithms can be concatenated in order to calculate many algorithms in one pass

I/O Related Features

  • Calculate hashes from files, stdin, file lists or command line argument values
  • Process directories recursively, and limit the depth
  • Jacksum detects file system cycles for you and it bypasses those in order to avoid endless loops
  • It is aware of special files like FIFOs, and symlinks on Linux/Unix and system folders on Windows
  • Control how to handle symbolic links on files and/or directories
  • Unicode file name support
  • Specify the character set for both input and output: GB18030, UTF-8, UTF-16, UTF-16BE, UTF-16LE, UTF-32, UTF-32BE, UTF-32LE, etc.
  • It is large file aware, it can process filesizes up to 8 Exabytes (= 8,000,000,000 Gigabytes), presupposed your operating system respectively your file system is large file aware, too.

Format Output Features

  • By default, the output is 100% compatible to Unix-standard tools such as sum, cksum, md5sum and sha1sum, b2sum, etc.
  • Use comprehensive format options to get the output you need
  • Specify one of the supported encodings for the hash values: bin, dec, oct, hex lowercase, hex uppercase, base16, base32, base32-nopadding, base32hex, base32hex-nopadding, base64, base64url, bubblebabble, etc.
  • Create and use your own customized, user-defined output format and create ed2k-links, magnet-links, or patch the Solaris pkgmap format for instance

Integrity Verification Features

  • Include not only the hash, but also the file size and/or file modification timestamp of files for performing reliable integrity checks
  • Perform integrity checks, and detect ok, failed, missing, and new files
  • Use predefined compatibility files to read and write popular 3rd party format styles (GNU/Linux, BSD, SFV, FCIV, openssl, etc.)
  • Create and use your own compatibility files

Find Objects with Jacksum

  • Find the algorithm that was used to calculate a checksum/CRC/hash
  • Find all files that match a given hash value (find duplicates of a file)
Multi-Platform Support
  • Jacksum is cross platform (100 % Java), so you can run it on all common operating systems, such as:
  • Microsoft Windows 10,
  • GNU/Linux (e.g Ubuntu),
  • Unix (e.g. macOS) or
  • any other operating system with a Java Runtime Environment (JRE) or Java Development Kit (JDK).
Interaction with other Tools
  • Works with the SendTo-feature on many file browsers (e. g. macOS Finder, Microsoft Windows Explorer, Gnome Nautilus, KDE Konqueror, ROX Filer, etc.)
  • As it has a command line interface, Jacksum can be used in cronjobs and autostart environments
  • Jacksum returns an exit status which is dependent on the result of the calculation/verification process, so you can use Jacksum in scripts and batches and control the code flow in your own scripts
  • Use predefined compatibility files to read and write popular 3rd party format styles in order to interact with other tools (GNU/Linux, BSD, SFV, FCIV, openssl, etc.)


  • The program is mature and very stable
  • Specify your preferred level of verbosity
  • Obtain details for each algorithm, including comprehensive compatibility lists
Developer support
  • Entire source code has been opened, is hosted on GitHub, and accessible using git
  • The project has been mavenized with a pom.xml which makes it easy to work in your preferred IDE
  • Jacksum provides an API, so you can incorporate Jacksum in your own projects
  • Javadoc is available
  • Jacksum keeps compatibility with JDK 11, but takes all the advantages of  JDK 11+ if available



Das Team

Die Liste von Mitwirkenden finden Sie stets im neuesten Download und in der Copyright Sektion. Der Gründer und Leiter dieses Projektes ist Johann N. Löfflmann aus Deutschland. Seit 2002 arbeitet er in seiner Freizeit mit talentierten Menschen aus aller Welt zusammen, um Jacksum gemeinsam weiter zu verbessern.

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