Encryption

Some notes on recording encryption.

Stock firmware

• Every recording made by the Humax is encrypted before being stored on disk;
• The encryption key is unique to each box and believed to be stored in an on-chip Hardware Security Module (HSM);
• Copying a standard definition recording to an external disk (connected via USB) results in the Humax decrypting the file in the process [HDR model only];
• Copying a high definition recording to an external disk will NOT decrypt it;
• The HDR features a built-in FTP server but this only provides access to the raw files on disk. If you download files from the Humax via FTP, they will remain encrypted;
• The HDR features a built-in DLNA media server which serves decrypted content to DLNA clients. However, it will only stream high definition content to clients that negotiate Digital Transmission Content Protection (DTCP);

Custom firmware

If you install the custom firmware and install the right packages, then:

• High definition recordings can be treated in the same way as standard definition, i.e. decrypted on copy to external disk and streamed without DTCP;
• Decryption on copy can be achieved with a virtual disk (much faster);
• Recordings can be automatically decrypted in-place as a background task;
• Selected recordings can be decrypted in-place via the web interface;
• The HDR software can be temporarily loaded onto the HD in order to decrypt recordings.