How Does the Analog Hole Defeat DRM Copy Protection?

What does the analog hole mean for digital music?

Close up of guitar hold and guitar strings


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If you've never heard of the analog hole (or analog loophole as it is sometimes referred to), then you'll probably wonder what this strange term is all about. It isn't, of course, a hole in the true sense of the word, but a phrase that describes how digital copy protection can be defeated when analog techniques are used.

The ultimate goal using the analog hole is to bypass any copy restrictions imposed by creating an exact copy through the use of an analog recording.

Can't DRM Protected Files Just be Copied to Another Device?

As you might already be aware, digital media files such as music and movies can sometimes be copy-protected using a system called DRM (Digital Rights Management). You can copy DRM protected media files just like any other files, but they won't be usable.

This is because encryption is used to prevent the protected media files from being used even if they are distributed. You won't be able to use a DRM'd song on a computer or device that isn't registered as being authorized to play it.

If you've got a collection of old iTunes songs that pre-date 2009, then you may have already found out that they are unplayable on computers that aren't authorized in iCloud, or on non-Apple devices that can't be used with Apple's FairPlay DRM.

How Is the Analog Hole Used to Create a DRM-Free Version of a Song?

In the case of DRM'd digital music stored on a computer, this digital lock can be circumvented quite easily. It's done by recording the analog sound that is emitted from the computer's soundcard.

When you play any digital music file (regardless of DRM), the audio data inside it has to be converted to analog so you can hear it. This analog sound can then be easily captured (using specialized software) and converted back to digital. This effectively defeats any copy protection that is in the original file.

DRM removal programs that use the analog hole typically employ a virtual soundcard. This is used instead of the real hardware device in your system to capture the audio. The recorded sound is then converted back into digital form by encoding the data to a DRM-free format such as MP3, AAC, etc.

Is It Legal to Use It?

DRM is used to protect the rights of those who are the legal copyright holders. And, to ensure no illegal copies are created and distributed. So, is it legal to circumvent this system even by using the analog hole?

There's no absolute right, but if it's for your own use and you have legally purchased the media, then it is generally accepted that it's OK to make a backup copy.

As long as you don't distribute this media then recording a song, for example, is normally seen as acceptable.