time delay unlock private key.

[Uwe Brauer]

Hello

A Long time ago, IBM's proprietary  OS, called CMS had a particular
feature for the login:

It gave you three attempts to login in. If you failed there was a time
delay of 20 min, if you failed again, the time delay was prolonged to
one hour, and then I think to one day.

My private pgp and smime keys are secured by a password, but there is no
time delay, which makes a brute force attack possible.

Could a time delay be implemented similar to the one I just mentioned?

regards

Uwe Brauer