This drive supports AES 128 bit encryption as you can see here: ARK | Intel® SSD 520 Series (240GB, 2.5in SATA 6Gb/s, 25nm, MLC)
Can you be a little bit more specific about what you need?
This product is currently EOL (End of Life).
I do not know how to set up the encryption key.
Encryption is always running? How do I enable encryption? How to do it?
The Intel® SSD 520 Series are self encrypting drives, meaning that the date is encrypted by the SSD controller before being written to flash memory. If you need additional encryption to prevent unauthorized access to the data, you would have to look up for third-party tools that can do this job. Remember that you can also set up an ATA password to this drive.
*Be aware that if you set a password using ATA security, please make sure you have the password kept somewhere else because if you forget it, there is no way to reset it or access the drive.