cryptsetup-benchmark(8) — Linux manual page



NAME         top

       cryptsetup-benchmark - benchmarks ciphers and KDF

SYNOPSIS         top

       cryptsetup benchmark [<options>]

DESCRIPTION         top

       Benchmarks ciphers and KDF (key derivation function). Without
       parameters, it tries to measure few common configurations.

       To benchmark other ciphers or modes, you need to specify --cipher
       and --key-size options.

       To benchmark PBKDF you need to specify --pbkdf or --hash with
       optional cost parameters --iter-time, --pbkdf-memory or

       NOTE: This benchmark uses memory only and is only informative.
       You cannot directly predict real storage encryption speed from

       For testing block ciphers, this benchmark requires kernel
       userspace crypto API to be available (introduced in Linux kernel
       2.6.38). If you are configuring kernel yourself, enable
       "User-space interface for symmetric key cipher algorithms" in
       "Cryptographic API" section (CRYPTO_USER_API_SKCIPHER .config

       <options> can be [--cipher, --key-size, --hash, --pbkdf,
       --iter-time, --pbkdf-memory, --pbkdf-parallel].

OPTIONS         top

       --hash, -h <hash-spec>
           The specified hash is used for PBKDF2 and AF splitter.

       --cipher, -c <cipher-spec>
           Set the cipher specification string.

       --key-size, -s bits
           Sets key size in bits. The argument has to be a multiple of
           8. The possible key-sizes are limited by the cipher and mode

           See /proc/crypto for more information. Note that key-size in
           /proc/crypto is stated in bytes.

           This option can be used for open --type plain or luksFormat.
           All other LUKS actions will use the key-size specified in the
           LUKS header. Use cryptsetup --help to show the compiled-in

       --pbkdf <PBKDF spec>
           Set Password-Based Key Derivation Function (PBKDF) algorithm
           for LUKS keyslot. The PBKDF can be: pbkdf2 (for PBKDF2
           according to RFC2898), argon2i for Argon2i or argon2id for
           Argon2id (see Argon2
           <> for more info).

           For LUKS1, only PBKDF2 is accepted (no need to use this
           option). The default PBKDF for LUKS2 is set during
           compilation time and is available in cryptsetup --help

           A PBKDF is used for increasing dictionary and brute-force
           attack cost for keyslot passwords. The parameters can be
           time, memory and parallel cost.

           For PBKDF2, only time cost (number of iterations) applies.
           For Argon2i/id, there is also memory cost (memory required
           during the process of key derivation) and parallel cost
           (number of threads that run in parallel during the key

           Note that increasing memory cost also increases time, so the
           final parameter values are measured by a benchmark. The
           benchmark tries to find iteration time (--iter-time) with
           required memory cost --pbkdf-memory. If it is not possible,
           the memory cost is decreased as well. The parallel cost
           --pbkdf-parallel is constant and is checked against available
           CPU cores.

           You can see all PBKDF parameters for particular LUKS2 keyslot
           with cryptsetup-luksDump(8) command.

           NOTE: If you do not want to use benchmark and want to specify
           all parameters directly, use --pbkdf-force-iterations with
           --pbkdf-memory and --pbkdf-parallel. This will override the
           values without benchmarking. Note it can cause extremely long
           unlocking time. Use only in specific cases, for example, if
           you know that the formatted device will be used on some small
           embedded system.

           MINIMAL AND MAXIMAL PBKDF COSTS: For PBKDF2, the minimum
           iteration count is 1000 and maximum is 4294967295 (maximum
           for 32bit unsigned integer). Memory and parallel costs are
           unused for PBKDF2. For Argon2i and Argon2id, minimum
           iteration count (CPU cost) is 4 and maximum is 4294967295
           (maximum for 32bit unsigned integer). Minimum memory cost is
           32 KiB and maximum is 4 GiB. (Limited by addressable memory
           on some CPU platforms.) If the memory cost parameter is
           benchmarked (not specified by a parameter) it is always in
           range from 64 MiB to 1 GiB. The parallel cost minimum is 1
           and maximum 4 (if enough CPUs cores are available, otherwise
           it is decreased).

       --iter-time, -i <number of milliseconds>
           The number of milliseconds to spend with PBKDF passphrase
           processing. Specifying 0 as parameter selects the compiled-in

       --pbkdf-memory <number>
           Set the memory cost for PBKDF (for Argon2i/id the number
           represents kilobytes). Note that it is maximal value, PBKDF
           benchmark or available physical memory can decrease it. This
           option is not available for PBKDF2.

       --pbkdf-parallel <number>
           Set the parallel cost for PBKDF (number of threads, up to 4).
           Note that it is maximal value, it is decreased automatically
           if CPU online count is lower. This option is not available
           for PBKDF2.

       --batch-mode, -q
           Suppresses all confirmation questions. Use with care!

           If the --verify-passphrase option is not specified, this
           option also switches off the passphrase verification.

       --debug or --debug-json
           Run in debug mode with full diagnostic logs. Debug output
           lines are always prefixed by #.

           If --debug-json is used, additional LUKS2 JSON data
           structures are printed.

       --version, -V
           Show the program version.

           Show short option help.

       --help, -?
           Show help text and default parameters.

REPORTING BUGS         top

       Report bugs at cryptsetup mailing list
       <> or in Issues project section

       Please attach output of the failed command with --debug option

SEE ALSO         top

       Cryptsetup FAQ

       cryptsetup(8), integritysetup(8) and veritysetup(8)

CRYPTSETUP         top

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cryptsetup 2.6.1-git           2022-12-14        CRYPTSETUP-BENCHMARK(8)

Pages that refer to this page: cryptsetup(8)