Current versions (via Ubisoft Connect or Steam) support offline play, but the initial activation still requires an internet connection and a legitimate key tied to your account. Without that, no local key file will work.
Even if the key file is plain text, it cannot activate a pirated copy of Anno 2070 without also replacing the game’s main .exe (a crack). These cracks often disable online features, but worse—they can steal your Ubisoft or Steam credentials if you ever log in while using them. Anno 2070 Serial Number Key File
After massive community backlash, Ubisoft removed the activation limit but kept the online requirement. However, the key file remained on your system in %ProgramData%/Ubisoft/ANNO 2070/. Current versions (via Ubisoft Connect or Steam) support
While prosecuting individual downloaders is rare, distributing or using a key file to bypass DRM is a violation of the DMCA (Digital Millennium Copyright Act) in the US and similar laws worldwide. Your ISP may send warnings, and in extreme cases, Ubisoft has been known to permanently ban accounts tied to illegitimate keys. Even if the key file is plain text,
