The software reads the header of the .dlc file. It identifies the offset (where the data starts) and the size of the encrypted blocks.
Let’s walk through a simplified, hypothetical decryption of a GOG-style DLC package. dlc decrypt
When you purchase DLC—say, an expansion pack for The Witcher 3 or a character for Street Fighter 6 —the files are often already present on your hard drive (downloaded via a patch). However, they are locked behind a layer of encryption. Your purchase gives you a small decryption key or a license file that tells the game: "It is okay to read these locked files now." The software reads the header of the
Decryption is the process of extracting the original, human-readable download URLs from these encrypted containers. Because the links inside are secured with encryption standards, you cannot simply open them in a standard text editor to see the URLs. How DLC Decryption Works When you purchase DLC—say, an expansion pack for
Often used for legacy PlayStation content. CDecrypt: A popular tool for Wii U files.
Under the in the US and the EU Copyright Directive in Europe, circumventing encryption—even for content you own—is illegal under anti-circumvention clauses.
If you meant something else — e.g., — that would involve breaking DRM or encryption, which is generally illegal under laws like the DMCA.