Ignition problem in 2006 Ford Focus ZX3


My 2006 ZX3 Ford Focus, with roughly 25,000 miles, has an intermittent problem that the dealership cannot solve.
At times, when I turn the key, the ignition will not crank. After several attempts and many minutes, the car will eventually start.
The first dealership replaced the PCM and I went on my merry way. Then, roughly 1.5 years later, the problem resurfaced and I went to a different dealership. (The first dealership closed.) The second dealership doubted the the PCM was the problem; said it can't replicate the issue, so it said it won't replace or fix anything. That's understandable. But the problem still persists, and by definition an intermittent problem is not always replicable. Any ideas? The service man said the problem could be security in which the computer chip in the ignition is not talking to the chip in my car key. But that was a wild guess on their part, and they said there's no way to find out. Any else have any bright ideas?