Packet Handshake Timing to Prevent RTT-Based Privacy Leakage

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Solution Overview

Problem

The three-way handshake mechanism in packet-switched communication networks exposes handshake packets to eavesdropping, allowing unauthorized parties to derive privacy-sensitive information about the endpoints, such as their distance and identity, by measuring round trip times.

Innovation Solution

Introduce a predefined wait time during the connection establishment process, where nodes transmit connection establishing packets after a predefined wait time, making the solution to prevent unauthorized access to sensitive information by unauthorized parties, which are known or may be easily derived by unauthorized parties, which are known or may be easily derived by unauthorized parties, which are known or may be easily derived by unauthorized parties, which are known or may be easily derived by unauthorized parties, which are known or may be easily derived by unauthorized parties, which are known or may be easily derived by unauthorized parties, which are known or may be easily derived by unauthorized parties to solve the privacy exposure by introducing a predefined wait time during the connection establishment process, where nodes transmit connection establishing packets after a predefined wait time, preventing unauthorized parties from deriving privacy-sensitive information.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the three-way handshake mechanism is used for connection establishment, then the connection can be securely established with encryption, but the handshake packets themselves become vulnerable to eavesdropping and privacy extraction

Engineering Contradiction:
Improveconnection securityVSAvoidprivacy exposure
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary action by introducing a wait time mechanism before transmitting the third handshake packet. This preliminary delay prevents unauthorized parties from immediately analyzing the handshake sequence, thereby protecting privacy-sensitive information during the connection establishment phase while maintaining secure connection establishment.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If handshake packets are transmitted without encryption to enable authentication and key negotiation, then the connection establishment is efficient, but privacy-sensitive information can be derived from the packets

Engineering Contradiction:
Improveconnection establishment efficiencyVSAvoidprivacy information leakage
Core Design Contradiction:
ProductivityVSLoss of information

Solution Approach 1:

The patent uses an intermediary approach by introducing a wait time parameter that acts as a buffer between packet transmission and analysis. This intermediary delay prevents direct correlation of handshake packets by unauthorized parties, thereby reducing information loss while maintaining the efficiency of the handshake process.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Speed

If the third handshake packet is transmitted immediately after receiving the second packet, then the connection establishment is fast, but round trip time measurement becomes possible for privacy violation

Engineering Contradiction:
Improvehandshake speedVSAvoidposition tracking
Core Design Contradiction:
SpeedVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary action by implementing a wait time delay before transmitting the third handshake packet. This preliminary delay prevents immediate RTT measurement by unauthorized parties, thereby protecting position information while maintaining acceptable connection establishment speed through the optimized waiting period.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4367871B1Establishing a connection in a packet-switched communication network
Publication Date: 2025.12.17 TELECOM ITALIA SPA
  • EP4367871B1 patent drawingFigure 1
  • EP4367871B1 patent drawingFigure 2
  • EP4367871B1 patent drawingFigure 3a

AI summary

It is disclosed a method for establishing a connection between a first node and a second node of a packet-switched communication network, such as by means of a three-way handshake procedure. The first node transmits to the second node a first connection establishing packet; the second node, transmits to the first node a second connection establishing packet in response to reception of the first connection establishing packet; and the first node transmits to the second node a third connection establishing packet in response to reception of the second connection establishing packet, after a predefined wait time TW has lapsed since reception of the second connection establishing packet. The predefined wait time TW, randomly selected by the first node, prevents non authorized parties who might eavesdrop the connection establishing packets – typically non encrypted - from deriving information about the positions of the nodes during the connection establishment procedure.