If you need a truly portable DAW for a USB stick, offers an official portable mode. If you want Cubase legally, Steinberg offers a free 60‑day trial of the latest Cubase Pro on their website.
Technically, Steinberg (the developer of Cubase) does not officially release "Portable" versions of their software in the way that portable web browsers or text editors are released. DAWs require deep system integration for audio drivers and hardware dongles (e.g., the Steinberg USB-eLicenser). Cubase 5 Portable Free HOT- Download
If you are pursuing a "lifestyle" of entertainment production, inviting ransomware into your machine is the fastest way to kill your vibe. If you need a truly portable DAW for