expeditionradio writes: > > Bill N9DSJ wrote: > > Can see no valid reason for encryption on our frequencies. If one > > could provide an single example I would be interested...... > > Hi Bill, > > Hams should certainly have the capability to pass over-the-air > encrypted traffic or scrambled speech for emergencies and disaster > relief. There are other situations where it would be useful, too. In > order to have seamless capability in an emergency, hams should be > familiar and proficient with the use of it on a regular basis. > > Encryption should not be with the sole intent to obscure the content > from other hams, but it should be availble to hams when there is a > need to shield sensitive data and information from evil-doers. > > Here are a few reasons for hams to use limited encryption in the > over-the-air communication: > > 1. To shield private data > 2. To shield private telephone numbers > 3. To shield sensitive email addresses
The many administrations which don't permit amateurs to carry third party traffic at all (in many cases to protect their national government's monopoly position as a provider of secure radiocommunication within their borders) seem unlikely to agree to revise the International Radio Regulations in a way which would make it easier for their hams to conceal that they might be carrying third-party traffic. > 4. To shield system passwords Logins over potentially-compromised media (including ham radio) should use technical means to cryptographically authenticate transmissions, but that does not require cryptographic concealment of the content. If I chose, I could use private-key encryption to ssh into my shell account at my ISP, while passing the text of my session in the clear. Someone who sniffed my packets would be able to see what I was doing during my session at my ISP, but would not be able to masquerade as me using the information gleaned from tapping my lines or sniffing my packets. Something similar involving, e.g., exponential key exchange, could be used over ham radio. Multiple-use passwords sent in the clear became obsolete for network use more than a decade ago: there is no reason why ham radio should adopt content encryption to make up for the weaknesses of such obsolete methods of authentication. > 5. To shield station remote control Concatenate the command and a timestamp, and use a crytographically strong a hash of the combination to prove that the command comes from someone authorized to remotely control the station, and to prevent replay attacks. There is no need to cryptographically conceal the command itself, only to cryptographically sign it. Challenge-response single-use passwords are another possible solution, still not requiring cryptographic concealment. > 6. To secure access to stations Same answer as number 4 or 5, depending on what exactly is meant by that. > 7. To control satellites The same as number 5. (ISTR that crypto concealment for control of ham satellites is already authorized, but I assert that there is no technical need for it: crypto authentication would be sufficient.) > 8. To shield messages sent by a 3rd party to ham Same answer as numbers 1-3. > 9. To protect medical information Now we *may* be getting somewhere, but I'm still not sure. It seems to me that, e.g., a hospital could call via ham radio for helicopter evacuation of a patient to a regional trauma center, providing sufficient information about the case to justify dispatching the helicopter, but provide the actual name of the patient to the EMTs along with the patient's file and the patient himself when the helicopter arrives, rather than by radio. Is it really necessary to transmit personally-identifiable medical information over ham radio in emergencies? > 10. To protect 3rd party traffic requiring confidentiality See reply to items 1-3. > 11. To control repeaters See reply to item 5. > 12. To shield identities of children It's not clear to me exactly what that means. > I'm sure there are more reasons... but that's some of the things I > thought of in the few minutes it took to write this. > > Bonnie KQ6XA It may be that I am wrong, that Bonnie is right, and that the world at large (not just the FCC) is willing to permit hams to conceal the content of our traffic by cryptographir means, but I don't see a lot of evidence of that yet. It also may be that, say, on 2M and above, where F-layer propagation is unknown, hams could be permitted the use of crypto without disturbing international agreements too much. -- 73 DE KW6H (ex AE6VW), Chris Jewell [EMAIL PROTECTED]
