Blue-Merle — IMEI rotation on the move

Blue-Merle is an open-source tool against movement tracking via your mobile router’s hardware identifier. Originally developed by SR Labs (Security Research Labs) from Berlin — as a free FOSS project on GitHub.

What it is

Every mobile modem broadcasts a fixed device identifier, the IMEI. Carriers see it on every registration — even when you swap the SIM. Via the IMEI, different SIMs can be tied to the same device and turned into movement profiles. blue-merle addresses exactly this: it randomises the device identity on SIM change and clears related traces.

Why it matters

• Break cross-SIM correlation: a rotating IMEI makes it harder to merge multiple SIM cards into “one device”.
• FOSS & auditable: the code is open — you don’t have to trust anyone, you can read it.
• Free & open: no vendor turning you into the product.

Honest note

blue-merle is a specialised tool for certain mobile hotspot routers — not a universal cloak. But for people who care about mobility privacy, it’s a solid building block. As always: your threat model decides whether the effort is worth it.