Now we have these awesome updates from flatz, who has released Disc Key Dumper, Klicensee Dumper and Secure File ID Dumper for use on 4.21 CFW, here is a quote from the awesome dev

Finally I was able to find the time to port my dumpers on 4.21 CFW. There were some problems while porting from 3.55 to 4.xx and hopefully all of them were fixed.Download
These dumpers are not required to work with previous tool called Data Ddumper because they just write all data directly to the corresponding file on /dev_hdd0/tmp.
All dumpers were tested on 4.21 REX and should works fine if you do the process correctly.
I recommend to use the FTP client from multiMAN to patch sprx files.
Don’t forget to make backups of sprx files before patching them.
Don’t use two or more dumpers at once – this will definitely not work).
Thanks for your hard work flatz, Merry Christmas :)
Follow flatz on Twitter.
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