Decryption Keys

How freemkv decrypts a disc depends on its format: DVDs need nothing, while Blu-ray and 4K UHD need keys you supply.

DVD

DVDs decrypt automatically. There are no keys to install and nothing to configure.

Blu-ray and 4K UHD

Format	Encryption
Blu-ray	AACS 1.0
4K UHD	AACS 2.0 / 2.1

AACS-encrypted discs decrypt only when you supply AACS keys. No AACS keys are built in. Provide them one of two ways: an online key service or a local keydb.cfg. freemkv-library, the freemkv CLI, and the desktop app all support either source — the desktop app shows which one resolved the disc’s key right in its key-state line.

You supply the keys

freemkv ships with no AACS keys built in, and this website does not link to, host, or recommend any specific online key service or key database. The options below describe the mechanisms only; obtaining keys is up to you.

Online key service

A third-party web service looks up keys for an inserted disc on demand, so you don’t maintain a local file — and it’s generally much more compatible with AACS 2.0+ discs. Reach out on our support Discord for more access information.

In freemkv-library, enable the online key service and set its URL under Settings. See freemkv-library.

In the CLI, point at the service with --key-url (and --key-auth if it requires a bearer token):

# resolve keys from an online key service — main title only
freemkv disc:// -t 1 mkv://Movie.mkv --key-url https://keys.example/keys

# with an authentication token
freemkv disc:// -t 1 mkv://Movie.mkv --key-url https://keys.example/keys --key-auth <TOKEN>

For title selection and source/destination behavior, see the CLI reference. For how --key-url and --keydb interact (local-first) and the SSRF guard on the service URL, see CLI → Flags.

Local keydb.cfg

A keydb.cfg file on disk. It is the single source of AACS truth — no AACS keys are compiled into the freemkv binary. The file holds the AACS material freemkv draws on to unlock a disc: device keys (DKs), processing/player keys (PKs), host certificates for the drive’s secure handshake, and per-disc entries — a Volume Unique Key (VUK), unit (title) keys, or a Media Key.

By default the CLI looks for it next to the freemkv executable — a keydb.cfg in the same folder as the program. freemkv is a portable, self-contained binary, so its key database lives beside it rather than in an OS configuration directory.

Refresh it from a URL with the update-keys command — see the CLI reference for the full syntax and supported formats (.txt / .zip / .gz). The short version writes keydb.cfg next to the executable:

freemkv update-keys --url <KEYDB_URL>

The global --keydb flag points the CLI at a keydb.cfg anywhere — on update-keys to download there, and on a rip to read from there:

freemkv update-keys --keydb /path/to/keydb.cfg --url <KEYDB_URL>   # download to a custom path
freemkv disc:// -t 1 mkv://Movie.mkv --keydb /path/to/keydb.cfg     # rip using it

freemkv-library is a long-running service rather than a portable binary, so it uses the standard config location ~/.config/freemkv/keydb.cfg and can also download and refresh the file for you from Settings. For the Docker image, bind-mount a host keys directory to /root/.config/freemkv (see freemkv-library → Deploy) so it persists across restarts.

When keys are missing

If you rip an AACS-encrypted disc with no key source configured, freemkv fails loudly and early — a clear error message, non-zero exit, and no output file written. It never writes a silently-encrypted or partially-decrypted file. On a multi-title rip (-t all / multiple -t N), it stops after the first title’s failure instead of repeating the same error for every remaining title. freemkv-library marks the disc “Missing keys — no key source has a key for this disc” and, when nothing is configured at all, prompts “No keys are available. Configure a key source in Settings.” DVDs are never affected.