License / Registration key enabled software

[Mike Playle]

On Fri, 22 Sep 2006 11:51:01 -0700, T wrote:

> We all know that there are many softwares that require some license key
> or registration key to enable them.  How does one implement something
> like this in python?

Here's a slightly different take on license keys that
nobody else has mentioned:

License keys exist to make it easier for honest users to
remain honest. Since any scheme can be cracked, dishonest
users will use your software without paying for it with
or without a license key scheme, so there's no point
spending much effort on the dishonest. Focus instead on
what your honest users want.

For instance a customer might want to buy a license to
use your software on up to 5 machines at once, but still
have the software installed on every machine in the
company. License systems like FlexLM can work here, to
make it easier for them to ensure that they comply with
the terms of the license.

Forget about the people who'll crack your software. Ask
yourself whether a license key scheme offers anything
to the people who won't try to crack it. If it does, then
actually implementing the scheme becomes trivial; if it
doesn't, then leave it out, because it won't help against
crackers.

Mike