The .bin extension stands for "binary." An file is a data container that holds a cryptographic key. This key is used by software to either encrypt (lock) or decrypt (unlock) specific information.
Tools like OpenIV for Grand Theft Auto V require an encryption_key.bin to access and edit game archives. Encryption-key.bin File Download
The file contained a hidden partition, not visible to the naked eye. The partition was encrypted with a custom algorithm, and Emily couldn't crack it using conventional methods. She suspected that this might be a red herring, designed to throw analysts off the scent. Encryption-key.bin File Download