Nah, it differs between the Bluetooth device profiles, and even wildly within each profile. Audio headsets are particularly weak - Ostensibly using a '128 bit'

Nah, it differs between the Bluetooth device profiles, and even wildly within each profile. Audio headsets are particularly weak - Ostensibly using a '128 bit' cypher in many instances which turns out to be the c0 stream cypher, proven to be weak and effectively only 56 bit. The situation is exacerbated by how little product manufacturers have to say on the subject.