Because these keys are sensitive, direct links often expire or are removed. You can typically find a "live" version by searching for these specific Pastebin or Archive identifiers:
Once the retail encryption key was public, it took less than a week for developers to update and amiitool (a command-line crypto library). Suddenly, anyone with a $2 pack of NTAG215 stickers and an Android phone could: amiibo retail encryption key pastebin