Three codes were hidden in the HTML source of the THE THIRD JOURNEY: UNBOUNDED post on the Investigate Ingress blog.
[1] 5kmt67r0n50b621zzx
[2] 8e7b6fafab79967d8c7b9a7caaa9a97a86
[3] 9p8uxerujri4h4a7
Code #1
Observations
18 characters, you have a bit more numbers than you need but it will help you get the keyword
Code #2
Observations
Look like hex but it needs a small manipulation
Code #3
Observations
16 characters with the right amount of numbers for a valid passcode