I have the same problem on Nifi 1.5 and would be very interested to get the solution to get Nifi's En(De)crypt processor to work with PGP.
In the meantime I turned to another solution by using the ExecuteStreamCommand processor and outsource the decryption to the CLI which is verified to work:
![92793-screen-shot-2018-10-11-at-100841-am.png 92793-screen-shot-2018-10-11-at-100841-am.png](https://community.cloudera.com/t5/image/serverpage/image-id/16720i0729DE5A6A5B29A7/image-size/medium?v=v2&px=400)
Just be aware that you have to import the pub and private keys into the /home/nifi/.gnupg folder of the nifi user since that is the one executing the stream command.
So you might have to run these commands (on every Nifi node!) first:
gpg --import < pub_keys_armor.pgp
gpg --import < priv_key_armor.pgp