Their design considerations aren't all that surprising. I was hoping they would describe solutions more in the document but they don't. It's mostly a "what do CBDCs need in the context of offline payments."
Sounds like they're contracting with the private sector:
A small but growing number of offline payment solutions are being developed by the private sector that can potentially be used for CBDC. The maturity and scale of these solutions vary. All of the solution vendors have highlighted the variety of complex challenges that are faced when developing an offline payments solution.
In total, 12 solution vendors participated in the deep-dive process.
Some solution vendors offer an end-to-end CBDC solution, of which offline payments with CBDC is one aspect. Other solution vendors only offer the offline payments solution, which they suggest can be integrated into an online solution. In both cases, the offline system will have dependencies on an online system.
Solution vendors demonstrated multiple communication methods including NFC, BLE, QR,strings of text and acoustic messages. The transfer protocol itself should ensure value can never be created and should minimise the scope for transactions to be torn and for value to be lost.
Solution vendors (listed in acknowledgements):
  • BitMint
  • Crunchfish
  • FIS Global and M10 Networks
  • Giesecke+Devrient
  • Google
  • IBM
  • IDEMIA
  • SWN Global
  • Thales and Secretarium
  • ToneTag
  • WhisperCash
  • Worldline