Since version 3.1, GD Rating System Pro has a new very useful security-related feature: it can store voters IP’s as MD5 hashed strings in the database.
The main purpose of this feature is to never store actual IP users used when voted, protecting the user privacy. But, since the MD5 hashes will be unique for each IP available, these strings can still be used to prevent duplicated votes and to track votes, and behave as regular IP’s would. Thera are few downsides of this method: you can’t see IP column in the votes log, or any IP related information (geolocation), you can’t see IP information in the dashboard votes widget.
Once you switch to MD5 hashed IP’s, if you decide to later disable this option, all previously hashed IP’s can’t be converted back to IP’s, the hash process is only one way. Once you decide to switch to MD5 hashed IP’s, there is no going back.
Enable MD5 hashed IP’s
To start with this feature, you need to first enable the MD5 hashed IP’s from plugins settings. Open Settings -> Security -> Use hashed IP, and enable MD5 hashed IP option. From this moment on, all IP’s will be stored as MD5.
Hash the existing log entries
For all this to work properly, you need to hash all the previously logged IP’s with MD5. To do this, open Tools -> MD5 hash IP’s, enable MD5 hash all IP’s and click Hash IP’s button. Now, the whole log has IP’s hashed with MD5.