  In a distributed quantum computer scalability is accomplished by networking
together many elementary nodes. Typically the network is optical and inter-node
entanglement involves photon detection. In complex networks the entanglement
fidelity may be degraded by the twin problems of photon loss and dark counts.
Here we describe an entanglement protocol which can achieve high fidelity even
when these issues are arbitrarily severe; indeed the method succeeds with
finite probability even if the detectors are entirely removed from the network.
An experimental demonstration should be possible with existing technologies.
