Could be the first part is a hash to verify the message and the second part is the encryption key ( or vice versa). Though it would make much more sense ( and be more secure - since the key would be much longer instead of being half as long by splitting it) to take the hash of the file and then use that hash key as the encryption key. Thus when it is decrypted using the key, you can then run a hash on the file and you have an instant hash verifier ( the key itself )
'GgWtjzMlc0fk1J4S\x00\x00\t\x07\x84\xb4\xf7\x87v\x16\x86\xf7\xa77W\x07W6'
Notice that the part before the 0000 is all printable 7-bit ASCII, whereas the stuff after is arbitrary binary garbage.
Perhaps the first part is a stream cipher key, and the second is a nonce to be combined with the key to decrypt a particular file. Although one would normally store the nonce prepended to the encrypted file.
I suspect a lot of this isn’t easily grasped by most folks. With good reason, it’s not something that they really need to know or run into very often.
I didn’t get into it much myself until I started with Linux - it doesn’t take too long before even the novice Linux user learns about checksums.
Encryption is a bit different than just verification, but it goes hand in hand with it.
Have to wait and see if this is something for public consumption/distribution or if it’s something more like him just verifying to someone else that “he’s really him” or the like.
But something sure has suddenly gotten into Hillary’s bonnet re:Wikileaks:
Clinton says WikiLeaks is now a ‘subsidiary of Russian intelligence’
https://www.theguardian.com/us-news/2017/oct/16/clinton-says-wikileaks-is-now-a-subsidiary-of-russian-intelligence
Hillary Clinton accuses WikiLeaks of blunting impact of crude Trump tape
http://indianexpress.com/article/world/hillary-clinton-accuses-wikileaks-of-blunting-impact-of-crude-us-president-donald-trump-tape-julian-asange-4892469