From a security PoV this is basic security by obscurity and effectively pointless - they are simply XORing each byte with a fixed value and then base64 encoding it - since the source code is public anyone can easily find this out and hence easily decode it - the only way to do this securely would be to have the DBus peers negotiate a session key and encrypt it properly using this - so I don't think there is any point adding this faux-encryption in this case.
From a security PoV this is basic security by obscurity and effectively pointless - they are simply XORing each byte with a fixed value and then base64 encoding it - since the source code is public anyone can easily find this out and hence easily decode it - the only way to do this securely would be to have the DBus peers negotiate a session key and encrypt it properly using this - so I don't think there is any point adding this faux-encryption in this case.