Re: Using Proxy Re-Encryption for vehicle data sharing

Hi all,

In line with the discussions today, here is a reference to a more recent PRE schemes that could fit better our use case:

Conditional Proxy Broadcast Re-Encryption:
https://www.researchgate.net/profile/Robert_Deng2/publication/220798629_Conditional_Proxy_Broadcast_Re-Encryption/links/0fcfd510b06d0e788b000000/Conditional-Proxy-Broadcast-Re-Encryption.pdf <https://www.researchgate.net/profile/Robert_Deng2/publication/220798629_Conditional_Proxy_Broadcast_Re-Encryption/links/0fcfd510b06d0e788b000000/Conditional-Proxy-Broadcast-Re-Encryption.pdf>

"A CPBRE scheme allows Alice to generate a re-encryption key for some condition specified during the encryption, such that the re-encryption power of the proxy is restricted to that condition only. This enables a more fine-grained delegation of decryption right. Moreover, Alice can delegate decryption rights to a set of users at a time. That is, Alice’s ciphertexts can be re-broadcasted. This saves a lot of computation and communication cost.”

It is in some way combining sticky policies concept with PRE in the same primitive. If you find that’s interesting, we can discuss it in the next Best Practices meeting. I am not familiar with this scheme in particular, but I think it is more important to discuss if the properties of the scheme are good for the use case rather than trying to perform a security analysis, which would take some time ...

Best,

Isaac.


> El 12 ene 2021, a las 17:54, Isaac Agudo Ruiz <isaac@lcc.uma.es> escribió:
> 
> Hi all,
> 
> I think this short video clearly explains the use of Proxy Re-Encryption (PRE) for data sharing in the vehicle ecosystem.
> 
> https://www.youtube.com/watch?v=MPsNLl6NWbo <https://www.youtube.com/watch?v=MPsNLl6NWbo>
> 
> There is also some documentation in the NuCypher website: https://www.nucypher.com/proxy-re-encryption <https://www.nucypher.com/proxy-re-encryption>
> 
> To support that Proxy Re-Encryption is not something new, this is the first paper where Proxy Re-encryption was defined, it is from 1998 ...
> https://www.researchgate.net/publication/221348480_Divertible_Protocols_and_Atomic_Proxy_Cryptography <https://www.researchgate.net/publication/221348480_Divertible_Protocols_and_Atomic_Proxy_Cryptography>
> 
> Of course, there are plenty of PRE schemes now a days with different security properties, variable performance and assumptions but in general, the “Proxy” should be neutral and not trying to colude with any of the parties involved in the data exchange.
> 
> We can discuss PRE and other approaches for secure vehicle data sharing in the next Best Practices meeting.
> 
> Isaac.