How does Samsung implement SD card encryption? My android device just stopped working. I still have my SD card, but all data in it is encrypted. Encryption has been performed at file level, so I have the directory structure and filenames in plain text, but file contents are encrypted.

I remember the key I used to set up encryption, but I need to know what algorithm did Samsung use for encryption and how they generated an encryption key from my passphrase.

Does anyone know if I can recover my data without the original device, using openssl or a similar program?
Samsung uses its own solutions for sdcard encryption in android device at file level.
Only device which encrypted the sdcard can decrypt it because when sdcard is encrypted an encryption policy file is saved into device and sdcard.
If you insert encrypted sdcard into other device then you will only will able to see the encrypted contents of those files.

So,if you have the same device which encrypted the sdcard and you know the lockscreen which was used to encrypt it then you can easily decrypt the sdcard by navigating as below :

Settings -> Security -> Encrypt External Sdcard -> Disable/Turn off

A notification pop up will appear for decrypting sdcard on your device