"The device-mapper disk driver first appeared in NetBSD 6.0.
It was then brought into DragonFly 2.7 by Alex Hornung." [0][1]
Don't know about NetBSD and Crypto-DM, but
"DragonFly has a device mapper target called dm_target_crypt(4) (compatible with Linux's dm-crypt) that provides transparent disk encryption. It makes best use of available cryptographic hardware, as well as multi-processor software crypto.
DragonFly fully supports LUKS (cryptsetup(8)) and TrueCrypt as disk encryption methods. tcplay(8), is a free (BSD-licensed) 100% compatible TrueCrypt implementation built on dm_target_crypt(4)." [2]
"The device-mapper disk driver first appeared in NetBSD 6.0. It was then brought into DragonFly 2.7 by Alex Hornung." [0][1]
Don't know about NetBSD and Crypto-DM, but
"DragonFly has a device mapper target called dm_target_crypt(4) (compatible with Linux's dm-crypt) that provides transparent disk encryption. It makes best use of available cryptographic hardware, as well as multi-processor software crypto.
DragonFly fully supports LUKS (cryptsetup(8)) and TrueCrypt as disk encryption methods. tcplay(8), is a free (BSD-licensed) 100% compatible TrueCrypt implementation built on dm_target_crypt(4)." [2]
[0] https://man.netbsd.org/dm.4 [1] https://man.dragonflybsd.org/?command=dm§ion=4 [2] https://www.dragonflybsd.org/features/#index6h2