None of those busses are encrypted (at least not the majority I am familiar with). The security gateway is just a firewall.
Toyota TSS3 is in fact encrypted; openpilot users who have TSS3 have to manually extract decryption keys from their cars to be able to talk on the CAN bus.
alt Hacker News
Toyota TSS3 is in fact encrypted; openpilot users who have TSS3 have to manually extract decryption keys from their cars to be able to talk on the CAN bus.