# cryptsetup-reencrypt

## NAME



           cryptsetup-reencrypt - reencrypt LUKS encrypted volumes in-place
    


## SYNOPSIS



           **cryptsetup** _reencrypt_ **[ <options>] <device> or --active-name <name>**
           **[ <new_name>]**
    


## DESCRIPTION



           Run LUKS device reencryption.
    
           There are 3 basic modes of operation:
    
           •   device reencryption (_reencrypt_)
    
           •   device encryption (_reencrypt_ --encrypt/--new/-N)
    
           •   device decryption (_reencrypt_ --decrypt)
    
           <device> or --active-name <name> (LUKS2 only) is mandatory
           parameter.
    
           Cryptsetup _reencrypt_ action can be used to change reencryption
           parameters, which otherwise require full on-disk data change
           (re-encryption). The _reencrypt_ action reencrypts data on the LUKS
           device in-place.
    
           You can regenerate **volume key**(the real key used in on-disk
           encryption unlocked by passphrase), **cipher** , **cipher mode** or
           **encryption sector size**(LUKS2 only).
    
           If you need to use both luksChangeKey and reencrypt (e.g., to
           recover from a leak), you need to use them in that order to avoid
           leaking the new volume key.
    
           The reencryption process may be safely interrupted by a user via
           SIGINT signal (ctrl+c). The same applies to the SIGTERM signal
           (i.e., issued by systemd during system shutdown).
    
           For in-place encryption mode, the _reencrypt_ action additionally
           takes all options available for the _luksFormat_ action for the
           respective LUKS version (see cryptsetup-luksFormat man page for
           more details). See cryptsetup-luksFormat(8).
    
           Note that for encrypt and decrypt mode, the whole device must be
           treated as unencrypted — there are no guarantees of
           confidentiality as part of the device contains plaintext.
    
           **ALWAYS BE SURE YOU HAVE RELIABLE BACKUP BEFORE USING THIS ACTION**
           **ON LUKS DEVICE.**
    
           **< options> **can be [--batch-mode, --block-size, --cipher, --debug,
           --debug-json, --decrypt, --device-size, --disable-locks,
           --encrypt, --force-offline-reencrypt, --hash, --header,
           --hotzone-size, --iter-time, --init-only, --keep-key, --key-file,
           --key-size, --key-slot, --keyfile-offset, --keyfile-size, --tries,
           --timeout, --pbkdf, --pbkdf-force-iterations, --pbkdf-memory,
           --pbkdf-parallel, --progress-frequency, --progress-json,
           --reduce-device-size, --resilience, --resilience-hash,
           --resume-only, --sector-size, --use-directio, --use-random,
           --use-urandom, --use-fsync, --uuid, --verbose, --volume-key-file,
           --write-log].
    


## LUKS2 REENCRYPTION



           With the <device> parameter, cryptsetup looks up the active
           <device> dm mapping. If no active mapping is detected, it starts
           offline LUKS2 reencryption; otherwise, online reencryption occurs.
    
           To resume already initialized or interrupted reencryption, just
           run the cryptsetup _reencrypt_ command again to continue the
           reencryption operation. Reencryption may be resumed with different
           --resilience or --hotzone-size unless implicit datashift
           resilience mode is used: either encrypt mode with
           --reduce-device-size option or decrypt mode with original LUKS2
           header exported in --header file.
    
           If the reencryption process was interrupted abruptly (reencryption
           process crash, system crash, or power off), it may require
           recovery. The recovery is run automatically on next activation
           (action _open_) when needed or explicitly by the user (action
           _repair_).
    
           The optional parameter <new_name> takes effect only with the
           encrypt option, and it activates device <new_name> immediately
           after encryption initialization is finished. That’s useful when
           the device needs to be ready as soon as possible and mounted
           (used) before full data area encryption is completed.
    


## LUKS1 REENCRYPTION



           The current working directory must be writable, and temporary
           files created during reencryption must be present. During
           reencryption, the LUKS1 device is marked unavailable and must be
           offline (no dm-crypt mapping or mounted filesystem).
    
           **WARNING** : The LUKS1 reencryption code is not resistant to hardware
           or kernel failures during reencryption (you can lose your data in
           this case).
    


## OPTIONS



           **--align-payload** _< number of 512 byte sectors>_ (DEPRECATED, use
           --offset)
               Align payload at a boundary of _value_ 512-byte sectors.
    
               If not specified, cryptsetup tries to use the topology info
               provided by the kernel for the underlying device to get the
               optimal alignment. If not available (or the calculated value
               is a multiple of the default), data is by default aligned to a
               1MiB boundary (i.e., 2048 512-byte sectors).
    
               For a detached LUKS header, this option specifies the offset
               on the data device. See also the --header option.
    
               This option is DEPRECATED and has an unexpected impact on the
               data offset and keyslot area size (for LUKS2) due to the
               complex rounding. For fixed data device offset, use --offset
               option instead.
    
           **--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.
    
           **--block-size** _value_ (LUKS1 only)
               Use re-encryption block size of _value_ in MiB.
    
               Values can be between 1 and 64 MiB.
    
           **--cipher** , **-c** _< cipher-spec>_
               **LUKS2** : Set the cipher specification string for the data
               segment only.
    
               **LUKS1** : Set the cipher specification string for the data
               segment and keyslots.
    
               The default cipher is applied if the cipher specification is
               omitted in encrypt mode.
    
               In reencrypt mode, if no new cipher specification is
               requested, the existing cipher will remain. The only exception
               is if the cipher is "cipher_null", then the default cipher is
               used.
    
               _cryptsetup --help_ shows the compiled-in defaults.
    
               If a hash is part of the cipher specification, then it is used
               as part of the IV generation. For example, ESSIV needs a hash
               function, while "plain64" does not and hence none is
               specified.
    
               For XTS mode, you can optionally set a key size of 512 bits
               with the -s option. Key size for XTS mode is twice that for
               other modes for the same security level.
    
           **--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.
    
           **--decrypt**
               Initialize (and run) device decryption mode.
    
           **--device-size** _size[units]_
               Instead of the real device size, use the specified value. It
               means that only the specified area (from the start of the
               device to the specified size) will be reencrypted.
    
               **LUKS2** : When used together with --reduce-device-size, only the
               initial _size_ value (--device-size parameter) of data is
               shifted backwards while being encrypted.
    
               The sum of --device-size and --reduce-device-size values must
               not exceed the real device size.
    
               **WARNING:** This is a destructive operation. Data beyond
               --device-size limit may be lost after the operation is
               finished.
    
               If no unit suffix is specified, the size is in bytes.
    
               Unit suffix can be S for 512 byte sectors, K/M/G/T (or KiB,
               MiB, GiB, TiB) for units with 1024 base or KB/MB/GB/TB for
               1000 base (SI scale).
    
           **--disable-blkid**
               Disable use of the blkid library for checking and wiping
               on-disk signatures.
    
           **--disable-keyring**
               Do not load the volume key in the kernel keyring; store it
               directly in the dm-crypt target instead. This option is
               supported only for the LUKS2 type.
    
           **--disable-locks**
               Disable lock protection for metadata on disk. This option is
               valid only for LUKS2 and is ignored for other formats.
    
               With locking disabled, LUKS2 images in files can be fully
               (re)encrypted offline without the need for superuser
               privileges provided that the used block ciphers are available
               in the crypto backend.
    
               **WARNING:** Do not use this option unless you run cryptsetup in a
               restricted environment where locking is impossible to perform
               (where /run directory cannot be used).
    
           **--encrypt** , **--new** , **-N**
               Initialize (and run) the device in-place encryption mode.
    
           **--force-no-keyslots**(LUKS2 only)
               Enforce initialization of reencryption operation with
               additional --volume-key-file, --new-volume-key-file,
               --volume-key-keyring or --new-volume-key-keyring parameters.
               It would result in the deletion of all remaining LUKS2
               keyslots containing the volume key.
    
               LUKS2 keyslot with the new volume key may be added after the
               reencryption operation is finished. See
               cryptsetup-luksAddKey(8) command.
    
               **WARNING:** Use with extreme caution! If you lose the volume key
               stored in a file or in a kernel keyring before adding the
               LUKS2 keyslot containing the new volume key, the device will
               become unusable, and all data will be lost.
    
           **--force-offline-reencrypt**(LUKS2 only)
               Bypass active device auto-detection and enforce offline
               reencryption.
    
               This option is useful especially for reencryption of LUKS2
               images put in files (auto-detection is not reliable in this
               scenario).
    
               It may also help in case active device auto-detection on a
               particular data device does not work or report errors.
    
               **WARNING:** Use with extreme caution! This may destroy data if
               the device is activated and/or actively used.
    
           **--force-password**
               Do not use password quality checking for new LUKS passwords.
    
               This option is ignored if cryptsetup is built without password
               quality checking support.
    
               For more info about password quality check, see the manual
               page for **pwquality.conf**(5) and **passwdqc.conf**(5).
    
           **--hash** , **-h** _< hash-spec>_
               **LUKS1:** Specifies the hash used in the LUKS1 key setup scheme
               and volume key digest.
    
               If this parameter is not specified, the default hash algorithm
               is always used for a new LUKS1 device header.
    
               **LUKS2:** Ignored unless new keyslot pbkdf algorithm is set to
               PBKDF2 (see --pbkdf).
    
           **--header** _< device or file storing the LUKS header>_
               Use a detached (separated) metadata device or file where the
               LUKS header is stored. This option allows one to store the
               ciphertext and LUKS header on different devices.
    
               If used with --encrypt/--new option, the header file will be
               created (or overwritten). Use with care.
    
               **LUKS2** : For decryption mode, the option may be used to export
               the original LUKS2 header to a detached file. The passed
               future file must not exist at the time of initializing the
               decryption operation. This frees space in the head of the data
               device so that data can be moved at the original LUKS2 header
               location. Later on, the decryption operation continues as if
               the ordinary detached header was passed.
    
               **WARNING:** Never put an exported header file in a filesystem on
               top of the device you are about to decrypt! It would cause a
               deadlock.
    
           **--help** , **-?**
               Show help text and default parameters.
    
           **--hotzone-size** _size_ (LUKS2 only)
               This option can be used to set an upper limit on the size of
               the reencryption area (hotzone). The _size_ can be specified
               with a unit suffix (for example, 50M). Note that the actual
               hotzone size may be less than specified <size> due to other
               limitations (free space in keyslots area or available memory).
    
               With decryption mode for devices with LUKS2 header placed in
               the head of the data device, the option specifies how large is
               the first data segment moved from the original data offset
               pointer.
    
           **--init-only**(LUKS2 only)
               Initialize reencryption (any mode) operation in LUKS2 metadata
               only and exit. If any reencrypt operation is already
               initialized in metadata, the command with --init-only
               parameter fails.
    
           **--iter-time** , **-i** _< number of milliseconds>_
               The number of milliseconds to spend with PBKDF passphrase
               processing for the new LUKS header.
    
           **--keep-key**
               **LUKS2** : Do not change the effective volume key, and change
               other parameters if requested.
    
               **LUKS1** : Reencrypt only the LUKS1 header and keyslots. Skips
               data in-place reencryption.
    
           **--key-file** , **-d** _file_
               Read the passphrase from the file.
    
               If the name given is "-", then the passphrase will be read
               from stdin. In this case, reading will not stop at newline
               characters.
    
               The --key-file option can be used only if there is only one
               active keyslot, or alternatively, also if --key-slot option is
               specified (then all other keyslots will be disabled in the new
               LUKS device).
    
               If this option is not used, cryptsetup will ask for all active
               keyslot passphrases.
    
           **--keyfile-offset** _value_
               Skip _value_ bytes at the beginning of the key file.
    
           **--keyfile-size** , **-l** _value_
               Read a maximum of _value_ bytes from the key file. The default
               is to read the whole file up to the compiled-in maximum that
               can be queried with --help. Supplying more data than the
               compiled-in maximum aborts the operation.
    
               This option is useful to cut trailing newlines, for example.
               If --keyfile-offset is also given, the size count starts after
               the offset.
    
           **--key-size** , **-s** _bits_
               **LUKS2** : Provide current key size in _bits_. The argument has to
               be a multiple of 8. Useful when specifying the size of the
               current volume key when no keyslot is active.
    
               **LUKS1** : See --new-key-size.
    
           **--key-slot** , **-S** _< 0-N>_
               For LUKS operations that add key material, this option allows
               you to specify which keyslot is selected for the new key.
    
               For reencryption mode, it selects a specific keyslot (and
               passphrase) that can be used to unlock the new volume key. If
               used, all other keyslots get removed after the reencryption
               operation is finished.
    
               The maximum number of keyslots depends on the LUKS version.
               LUKS1 can have up to 8 keyslots. LUKS2 can have up to 32
               keyslots based on keyslot area size and key size, but a valid
               keyslot ID can always be between 0 and 31 for LUKS2.
    
           **--keyslot-cipher** _< cipher-spec>_
               This option can be used to set specific cipher encryption for
               the LUKS2 keyslot area.
    
           **--keyslot-key-size** _< bits>_
               This option can be used to set a specific key size for the
               LUKS2 keyslot area.
    
           **--label** _< label>_,  **--subsystem** _< subsystem>_
               Set label and subsystem description for LUKS2 device. These
               are similar to filesystem labels. The label and subsystem are
               optional fields and can be later used in udev scripts to
               trigger user actions once the device marked by these labels is
               detected.
    
           **--luks2-keyslots-size** _size_
               This option can be used to set a specific size of the LUKS2
               binary keyslot area (key material is encrypted there). The
               value must be aligned to a multiple of 4096 bytes with a
               maximum size 128MB. The <size> can be specified with a unit
               suffix (for example, 128k).
    
           **--luks2-metadata-size** _size_
               This option can be used to enlarge the LUKS2 metadata (JSON)
               area. The size includes 4096 bytes for binary metadata (usable
               JSON area is smaller of the binary area). According to the
               LUKS2 specification, only these values are valid: 16, 32, 64,
               128, 256, 512, 1024, 2048 and 4096 kB. The <size> can be
               specified with a unit suffix (for example, 128k).
    
           **--new-key-size** _bits_
               Sets new key size in _bits_. The argument has to be a multiple
               of 8. The possible key sizes are limited by the new cipher and
               mode used in reencryption.
    
               See /proc/crypto for more information. Note that the key size
               in /proc/crypto is stated in bytes.
    
               **LUKS1** : If you are increasing key size, there must be enough
               space in the LUKS header for enlarged keyslots (data offset
               must be large enough), or reencryption cannot be performed.
    
               If there is not enough space for keyslots with the new key
               size, you can destructively shrink the device with
               --reduce-device-size option.
    
           **--new-volume-key-file** _file_
               Use (set) the new volume key stored in a file. The option must
               be paired with --new-key-size parameter when initializing the
               reencryption operation.
    
               **WARNING:** If you create your own volume key, you need to make
               sure to do it right. Otherwise, you can end up with a
               low-entropy or otherwise partially predictable volume key,
               which will compromise security.
    
           **--new-volume-key-keyring** _< key description>_
               Use (set) the new volume key stored in a keyring.
    
               The size of the key stored in a keyring must be compatible
               with the new cipher used in the reencryption operation. See
               /proc/crypto for more information. Note that the key size in
               /proc/crypto is stated in bytes.
    
               The _< key description>_ uses keyctl-compatible syntax. This can
               either be a numeric key ID or a string name in the format
               _% <key type>:<key name>_. See also the **KEY IDENTIFIERS** section
               of keyctl(1). When no _% <key type>:_ prefix is specified, we
               assume the key type is _user_ (default type).
    
               **WARNING:** If you create your own volume key, you need to make
               sure to do it right. Otherwise, you can end up with a
               low-entropy or otherwise partially predictable volume key,
               which will compromise security.
    
           **--offset** , **-o** _< number of 512 byte sectors>_
               Start offset in the backend device in 512-byte sectors. This
               option is only relevant for the encrypt mode.
    
               The --offset option sets the data offset (payload) of the data
               device and must be aligned to 4096-byte sectors (must be a
               multiple of 8). This option cannot be combined with
               --align-payload option.
    
           **--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
               <https://www.cryptolux.org/index.php/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 the _cryptsetup --help_ output.
    
               A PBKDF is used for increasing the dictionary and brute-force
               attack cost for keyslot passwords. The parameters can be time,
               memory and parallel cost.
    
               For PBKDF2, only the 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
               derivation.
    
               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 a particular LUKS2
               keyslot with the cryptsetup-luksDump(8) command.
    
               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 or cause out-of-memory conditions with
               unconditional process termination. 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 the maximum is 4294967295 (maximum
               for 32-bit unsigned integer). Memory and parallel costs are
               not supported for PBKDF2. For **Argon2i** and **Argon2id** , the
               minimum iteration count (CPU cost) is 4, and the maximum is
               4294967295 (maximum for a 32-bit unsigned integer). Minimum
               memory cost is 32 KiB and maximum is 4 GiB. If the memory cost
               parameter is benchmarked (not specified by a parameter), it is
               always in the range from 64 MiB to 1 GiB. Memory cost above
               1GiB (up to the 4GiB maximum) can be setup only by the
               --pbkdf-memory parameter. The parallel cost minimum is 1 and
               maximum 4 (if enough CPU cores are available, otherwise it is
               decreased by the available CPU cores).
    
               **WARNING:** Increasing PBKDF computational costs above the
               mentioned limits provides negligible additional security
               improvement. While elevated costs significantly increase
               brute-force overhead, they offer negligible protection against
               dictionary attacks. The marginal cost increase for processing
               an entire dictionary remains fundamentally insufficient.
    
               The hardcoded PBKDF limits represent engineered trade-offs
               between cryptographic security and operational usability. LUKS
               maintains portability and must be used within a reasonable
               time on resource-constrained systems.
    
               Cryptsetup deliberately restricts maximum memory cost (4 GiB)
               and parallel cost (4) parameters due to architectural
               limitations (like embedded and legacy systems).
    
               PBKDF memory cost mandates actual physical RAM allocation with
               intensive write operations that must remain in physical RAM.
               Any swap usage results in unacceptable performance
               degradation. Memory management often overcommits allocations
               beyond available physical memory, expecting most allocated
               memory to remain unused. In such situations, as PBKDF always
               uses all allocated memory, it frequently causes out-of-memory
               failures that abort cryptsetup operations.
    
           **--pbkdf-force-iterations** _number_
               Avoid the PBKDF benchmark and set the time cost (iterations)
               directly. It can be used only for a LUKS/LUKS2 device. See
               --pbkdf option for more info.
    
           **--pbkdf-memory** _number_
               Set the memory cost for PBKDF (for Argon2i/id, the number
               represents kilobytes). Note that it is the 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 the maximal value; it is decreased
               automatically if the CPU online count is lower. This option is
               not available for PBKDF2.
    
           **--progress-frequency** _seconds_
               Print a separate line every _seconds_ with reencryption
               progress.
    
           **--progress-json**
               Prints progress data in JSON format, which is suitable mostly
               for machine processing. It prints a separate line every half
               second (or based on --progress-frequency value). The JSON
               output looks as follows during progress (except it’s a compact
               single line):
    
                   {
                     "device":"/dev/sda",      // backing device or file
                     "device_bytes":"8192",    // bytes of I/O so far
                     "device_size":"44040192", // total bytes of I/O to go
                     "speed":"126877696",      // calculated speed in bytes per second (based on progress so far)
                     "eta_ms":"2520012",       // estimated time to finish an operation in milliseconds
                     "time_ms":"5561235"       // total time spent in IO operation in milliseconds
                   }
    
               Note on numbers in JSON output: Due to JSON parser
               limitations, all numbers are represented in a string format
               due to the need for full 64-bit unsigned integers.
    
           **--reduce-device-size** _size_
               This means that the last _size_ sectors on the original device
               will be lost, and data will be effectively shifted by the
               specified number of sectors.
    
               It could be useful if you added some space to the underlying
               partition or logical volume (so the ast _size_ sectors contains
               no data).
    
               For units suffix, see --device-size parameter description.
    
               **WARNING:** This is a destructive operation and cannot be
               reverted. Use with extreme care - accidentally overwritten
               filesystems are usually unrecoverable.
    
               **LUKS2** : Initialize LUKS2 reencryption with data device size
               reduction (currently, only encryption mode is supported). The
               last _size_ sectors on the original plaintext device is used for
               temporarily storing the original first data segment. The
               former first data segment is replaced with LUKS2 header (half
               the _size_ value), and plaintext data is shifted backwards
               (again half the _size_ value) while being encrypted.
    
               The recommended minimum size is twice the default LUKS2 header
               size (--reduce-device-size 32M) for encryption mode.
    
               The sum of --device-size and --reduce-device-size values must
               not exceed the real device size.
    
               **LUKS1** : Enlarge the data offset to the specified value by
               shrinking the device size.
    
               You cannot shrink the device by more than 64 MiB (131072
               sectors).
    
           **--resilience** _mode_ (LUKS2 only)
               Reencryption resilience _mode_ can be one of _checksum_ , _journal_
               or _none_.
    
               _checksum_ : default mode, where individual checksums of
               ciphertext hotzone sectors are stored, so the recovery process
               can detect which sectors were already reencrypted. It requires
               that the device sector write is atomic.
    
               _journal_ : The hotzone is journaled in the binary area (so the
               data are written twice).
    
               _none_ : Performance mode. There is no protection, and the only
               way it’s safe to interrupt the reencryption is similar to an
               old offline reencryption utility.
    
               Resilience modes can be changed unless _datashift_ mode is used
               for operation initialization (encryption with
               --reduce-device-size option).
    
           **--resilience-hash** _hash_ (LUKS2 only)
               The _hash_ algorithm is used with "--resilience checksum" only.
               The default hash is sha256. With other resilience modes, the
               hash parameter is ignored.
    
           **--resume-only**(LUKS2 only)
               Resume reencryption (any mode) operation that is already
               described in LUKS2 metadata. If no reencrypt operation is
               initialized, the command with --resume-only parameter fails.
               Useful for resuming the reencrypt operation without
               accidentally triggering a new reencryption operation.
    
           **--sector-size** _bytes_ (LUKS2 only)
               Reencrypt the device with a new encryption sector size
               enforced.
    
               **WARNING:** Increasing the encryption sector size may break the
               hosted filesystem. Do not run reencryption with
               --force-offline-reencrypt if unsure what block size the
               filesystem was formatted with.
    
               Note that using a sector size larger than the underlying
               storage device’s physical sector size may result in data
               corruption during unexpected power failures. A power failure
               during write operations may result in only partial completion
               of the encryption sector write, leaving encrypted data in an
               inconsistent state that cannot be properly decrypted.
    
           **--timeout** , **-t** _seconds_
               The number of seconds to wait before a timeout on passphrase
               input via terminal. It is relevant every time a passphrase is
               asked. It has no effect if used in conjunction with
               --key-file.
    
               This option is useful when the system should not stall if the
               user does not input a passphrase, e.g., during boot. The
               default is a value of 0 seconds, which means to wait forever.
    
           **--token-id**
               **LUKS2 reencryption initialization:** Specify what keyslots
               (associated with the selected token) to use for LUKS2
               reencryption. If the reencryption operation changes the
               effective volume key, only keyslots associated with the token
               and unlocked successfully will be available after the
               reencryption operation is finished.
    
               **LUKS2 reencryption resume:** Specify what token to use and allow
               the token PIN prompt to take precedence over the interactive
               keyslot passphrase prompt. If omitted, all available tokens
               (not protected by PIN) will be checked before proceeding
               further with the passphrase prompt.
    
           **--token-only**
               **LUKS2 reencryption initialization:** Specify that all keyslots
               associated with any token will be used for LUKS2 reencryption.
               If the reencryption operation changes the effective volume
               key, only keyslots associated with any token will be available
               after the reencryption operation is finished.
    
               **LUKS2 reencryption resume:** Do not proceed further with the
               action if the token-based keyslot unlock failed. Without the
               option, the action asks for a passphrase to proceed further.
    
               It allows LUKS2 tokens protected by PIN to take precedence
               over the interactive keyslot passphrase prompt.
    
           **--token-type** _type_
               **LUKS2 reencryption initialization:** Specify what keyslots
               (associated with the selected token type) to use for LUKS2
               reencryption. If the reencryption operation changes the
               effective volume key, only keyslots associated with the token
               type and unlocked successfully will be available after the
               reencryption operation is finished.
    
               **LUKS2 reencryption resume:** Restrict tokens eligible for
               operation to a specific token _type_. Mostly useful when no
               --token-id is specified.
    
               It allows LUKS2 _type_ tokens protected by PIN to take
               precedence over the interactive keyslot passphrase prompt.
    
           **--tries** , **-T**
               How often the input of the passphrase shall be retried. The
               default is 3 tries.
    
           **--type** _type_
               Specifies required (encryption mode) or expected (other modes)
               LUKS format. Accepts only _luks1_ or _luks2_.
    
           **--usage**
               Show short option help.
    
           **--use-directio**(LUKS1 only)
               Use direct-io (O_DIRECT) for all read/write data operations
               related to the block device undergoing reencryption.
    
               Useful if direct-io operations perform better than normal
               buffered operations (e.g., in virtual environments).
    
           **--use-fsync**(LUKS1 only)
               Use the fsync call after every written block. This applies to
               reencryption log files as well.
    
           **--use-random** , **--use-urandom**
               Define which kernel random number generator will be used to
               create the volume key.
    
           **--uuid** _UUID_
               When used in encryption mode, use the provided _UUID_ for the
               new LUKS header instead of generating a new one.
    
               **LUKS1 (only in decryption mode)** : To find out what _UUID_ to
               pass, look for temporary files LUKS-_UUID_.[|log|org|new] of the
               interrupted decryption process.
    
               The _UUID_ must be provided in the standard UUID format, e.g.,
               12345678-1234-1234-1234-123456789abc.
    
           **--verify-passphrase** , **-y**
               When interactively asking for a passphrase, ask for it twice
               and complain if both inputs do not match. Ignored on input
               from file or stdin.
    
           **--version** , **-V**
               Show the program version.
    
           **--volume-key-file** _file_ , --master-key-file file (OBSOLETE alias)
               **LUKS2** : Provides the current volume key stored in a file. It
               can be used to reencrypt the device with no active keyslot
               together with --new-volume-key-file or
               --new-volume-key-keyring options.
    
               **LUKS1** : See --new-volume-key-file.
    
           **--write-log**(LUKS1 only)
               Update the log file after every block is written. This can
               slow down reencryption, but it will minimize data loss in the
               case of a system crash.
    


## EXAMPLES



           You may drop **--type luks2** option as long as LUKS2 format is
           default.
    
       **LUKS2 ENCRYPTION EXAMPLES**
           Encrypt LUKS2 device (in-place). Make sure the last 32 MiB on
           _/dev/plaintext_ is unused (e.g., does not contain filesystem data):
    
           **cryptsetup reencrypt --encrypt --type luks2 --reduce-device-size**
           **32m /dev/plaintext_device**
    
           Encrypt LUKS2 device (in-place). Only the initial 1 GiB of
           original _/dev/plaintext_ data is encrypted while being shifted
           backwards. Make sure the last 32 MiB (tail) on the data device is
           unused (e.g., does not contain any data):
    
           **cryptsetup reencrypt --encrypt --type luks2 --device-size 1g**
           **--reduce-device-size 32m /dev/plaintext_device**
    
           Encrypt LUKS2 device (in-place) with detached header, put in a
           file:
    
           **cryptsetup reencrypt --encrypt --type luks2 --header**
           **my_luks2_header /dev/plaintext_device**
    
           Initialize LUKS2 in-place encryption operation only and activate
           the device (not yet encrypted):
    
           **cryptsetup reencrypt --encrypt --type luks2 --init-only**
           **--reduce-device-size 32m /dev/plaintext_device**
           **my_future_luks_device**
    
           Resume online encryption on the device initialized in the example
           above:
    
           **cryptsetup reencrypt --resume-only /dev/plaintext_device** or
           **cryptsetup reencrypt --active-name my_future_luks_device**
    
       **LUKS2 REENCRYPTION EXAMPLES**
           Reencrypt LUKS2 device (refresh volume key only):
    
           **cryptsetup reencrypt /dev/encrypted_device**
    
           Reencrypt LUKS2 device using keyslot(s) associated with the token
           3. All other keyslots will be removed after the reencryption
           finishes.
    
           **cryptsetup reencrypt --token-id 3 /dev/encrypted_device**
    
           Reencrypt LUKS2 device using keyslots associated with all
           'systemd-tpm2' tokens. All other keyslots will be removed after
           the reencryption finishes.
    
           **cryptsetup reencrypt --token-type systemd-tpm2**
           **/dev/encrypted_device**
    
       **LUKS2 DECRYPTION EXAMPLES**
           Decrypt LUKS2 device with header put in the head of the data
           device (header file does not exist):
    
           **cryptsetup reencrypt --decrypt --header /export/header/to/file**
           **/dev/encrypted_device**
    
           Decrypt LUKS2 device with detached header (header file exists):
    
           **cryptsetup reencrypt --decrypt --header detached-luks2-header**
           **/dev/encrypted_device**
    
           Resume interrupted LUKS2 decryption:
    
           **cryptsetup reencrypt --resume-only --header luks2-hdr-file**
           **/dev/encrypted_device**
    


## CRYPTSETUP



           Part of cryptsetup project
           <https://gitlab.com/cryptsetup/cryptsetup/>. This page is part of
           the _Cryptsetup_ ((open-source disk encryption)) project.
           Information about the project can be found at 
           ⟨https://gitlab.com/cryptsetup/cryptsetup⟩. If you have a bug
           report for this manual page, send it to dm-crypt@saout.de. This
           page was obtained from the project's upstream Git repository
           ⟨https://gitlab.com/cryptsetup/cryptsetup.git⟩ on 2025-08-11. (At
           that time, the date of the most recent commit that was found in
           the repository was 2025-08-01.) If you discover any rendering
           problems in this HTML version of the page, or you believe there is
           a better or more up-to-date source for the page, or you have
           corrections or improvements to the information in this COLOPHON
           (which is _not_ part of the original manual page), send a mail to
           man-pages@man7.org
    
    cryptsetup 2.8.1-git            2025-08-09        _CRYPTSETUP-REENCRYPT_(8)
    


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