ICMP timestamp – firewall configured to drop timestamp request, but vulnerability scanner can send request and get a response

We use an external scanner (Qualys) to scan our external assets. We have a firewall in front of the external assets, but it is configured to whitelist the scanner so that the external assets get scanned in-depth. But the firewall is also c… Continue reading ICMP timestamp – firewall configured to drop timestamp request, but vulnerability scanner can send request and get a response

How can Alice ping and authenticate Bob without any of them sharing their public keyes beforehand

Both hosts have just their public and private key pair (but they do not have the other party’s public key).
Bob should be authenticated
Assume that the two hosts share clocks that are synced, i.e timestamps can be used.

I have not found … Continue reading How can Alice ping and authenticate Bob without any of them sharing their public keyes beforehand

Concatenating timestamp to data before encrypting it – is this a commonly used technique?

I have a web app that communicates with a backend server, and the users of the web app are organisations that each have a single login for the entire organisation. The app is meant to be used for example on TV’s in the cafeteria to display… Continue reading Concatenating timestamp to data before encrypting it – is this a commonly used technique?