Can you ask to see a copy of security guidelines: I would think the security guidelines are for internal company private conversations and communication with suppliers covered by Non-Disclosure.
If it's a public workshop it's not clear that they will be disclosing company private information: I don't think your workshop would trigger cases covered by the security restriction and should not be subject to security guideline.
I will soon be offering a workshop on Zoom and a potential participant asked:
" I¡¯m not allowed to use Zoom on my devices due to my workplace¡¯s security guidelines, will we be able to dial in without using the app?" It's important in our sessions that poeple can be on camera - and join in break outs etc.... Help me understand how to respond to the question!? Thank you