Section 1201 prohibits circumvention of access controls, regardless of whether the underlying use is fair. Even removing DRM to read a legally purchased book on a different device is a violation. No general "fair use" exception exists.
Amazon uses a PID (Personal Identification Number) or a serial number tied to a Kindle device. Newer KFX (Kindle Format 10) DRM adds a second layer of encryption. Removal tools often require the user’s actual Kindle serial number, effectively using legitimate authorization to derive the decryption key.
Most tools (e.g., DeDRM plugin for Calibre) operate not by breaking encryption cryptographically, but by extracting the key from an authorized instance of ADE or a registered Kindle device. This is a "side-channel" approach.
Some tools downgrade the eBook to an older DRM version (e.g., converting KFX to MOBI with an old Kindle for PC version) which has known vulnerabilities.
The sale of eBooks has surpassed print in many markets, yet purchasers often do not truly "own" their files. DRM encrypts an eBook to a specific device or user account, preventing transfer to non-compatible devices or archival backup. Frustrated by vendor lock-in, consumers have turned to DRM removal tools. This paper examines the mechanics of those tools and the legal risks they entail.
Adobe’s DRM ties an eBook to a user’s Adobe ID. The file is encrypted using AES-128, with the user key stored on Adobe’s activation servers. Removal typically involves exploiting the “default key” vulnerability or using authorized decryption via the Adobe Digital Editions (ADE) client memory dump.