plus an
		increasing counter. For example, first dynamically certificate has 
		serial number 2314, the second one 2315, the third one 2316 and so on.
		The reason for this is simple: browsers are also caching certificates.
		When you restart ZAP but don't restart your browser, it could happen,
		that the browser sees the same certificate but with different serial number.
		In the end, the browser would complain about and reject the certificate.
		By using the random offset (internally 48bit random number),