Solutions/Criteria

Security

Privacy

DP-3T

Vulnerable against Replay Attacks.

Encounters information can be revealed.

Interactive Protocol [7]

Prevent Replay Attacks if the same course times are used.

Digital evidence is protected only to a certain degree if small tags are used.

Delayed Authentication Scheme [8]

Probably prevents replay attacks.

Digital evidence about encounters can be revealed in parties deflecting from the protocol.

Our Proposed Solution

1. Prevents 100% of Replay attacks whereby Receiver’s location hash differs from Broadcast’s Location Hash.

2. Prevents 100% of Replay attacks whereby Receiver’s date time differs from Broadcast’s date time.

3. Prevents 100% of Total Replay attacks whereby broadcasts have different locations and different date times as compared to the receiver, ephemeral keys that have passed their validity period, and/or broadcasts that have already been received by the receiver.

4. Any broadcast that does not fulfil all four criteria needed to be accepted is automatically flagged as a replayed broadcast, resulting in an acceptance rate of only 9.10% in a batch of 11 receivers with variable locations and date times.

5. The acceptance rate can be increased by making date times or location coordinates coarser.

Location Hashes prevent encounters from being disclosed.