[Q&A]

[Ka213]

Python version (python3 -V)

3.9

NVFlare version (python3 -m pip list | grep "nvflare")

2.5.2

NVFlare branch (if running examples, please use the branch that corresponds to the NVFlare version, git branch)

2.5.2

Operating system

Ubuntu 20.04

Have you successfully run any of the following examples?

• hello-numpy-sag with simulator
• hello-pt with simulator
• hello-numpy-sag with POC
• hello-pt with POC

Please describe your question

I`m using the 3rd-party system integration of nvflare (https://nvflare.readthedocs.io/en/main/programming_guide/execution_api_type/3rd_party_integration.html). When updating the nvflare version from 2.5.1 to 2.5.2 the 3rd party systems cannot authenticate themselfes anymore:

2025-10-23 13:17:34,553 - TokenVerifier - ERROR - exception verifying token: client_name='site-1' token='NA': Error: Incorrect padding
2025-10-23 13:17:34,556 - FederatedServer - ERROR - unauthenticated msg (channel='sm__STREAM' topic='sm__DATA') received from site-1_site-1_active: invalid auth token signature

I think it has something to do with the message authentication which was included in version 2.5.2.

As minimal working example the code from https://nvflare.readthedocs.io/en/main/programming_guide/execution_api_type/3rd_party_integration.html can be used.