There are a couple of good solutions on Linux for encrypting disks and volumes. Ubuntu has its own LUKS based solution built in the OS. And then there was TrueCrypt. However, the latter was discontinued suddenly by the developer citing security issues with the encryption in TrueCrypt. Though nothing alarming could be found till date and the disappearance remains a mystery, users are on the lookout for a supported solution. TCnext is the new home of TrueCrypt but development is at a standstill. Enter VeraCrypt.
VeraCrypt is based on TrueCrypt and brings in massive improvements to the security algorithms. Here’s an example: TrueCrypt uses PBKDF2-RIPEMD160 with 1000 iterations whereas in VeraCrypt uses 327661. For standard containers and other partitions, TrueCrypt uses at most 2000 iterations but VeraCrypt uses 655331 for RIPEMD160 and 500000 iterations for SHA-2 and Whirlpool. While this multiplied security adds some delay (within acceptable threshold) to opening an encrypted volume, the usage phase remains unaffected.
An important point to note is that VeraCrypt format is incompatible with TrueCrypt format.
VeraCrypt is available for Linux, Windows and Mac.