### Abstract

Recently, the Secure Average Time Synchronization (SATS) protocol has been proposed and analyzed; this distributed clock synchronization protocol is capable of successfully tackling several attacks such as denial-of-service (DoS), message-delay, message duplication/repetition, and even a generic message manipulation. However, the collusion attack, in which neighboring malicious nodes may cooperate so as to strike stealthier attacks that are more difficult to handle, remains by and large an open problem. In the setup of SATS, we derive the fundamental asymptotic bounds in the number of malicious agents-as function of the benign ones-that can be efficiently handled without tampering accurate network-wide synchronization. Going a step further, we develop a risk model for collusions and use it to obtain even tighter bounds. In specific, we establish that SATS can handle 'many' malicious nodes with high probability: an order of almost square-root of the benign ones for the case of no risk, and almost linear when the risk of collusion is accounted. Last but not least, we analyze and experimentally assess an interesting phenomenon: the presence of attackers may lead to a convergence speedup of SATS, since malicious nodes can be effectively constrained from the network, thus affecting the algebraic connectivity of the graph corresponding to the network topology. Numerical simulations verify the theoretical results, i.e., collusions are avoided when the number of malicious nodes is bounded by the asymptotic bounds and the algebraic connectivity increases due to incorporating 'well behaved' malicious nodes.

Original language | English (US) |
---|---|

Title of host publication | 54th Annual Allerton Conference on Communication, Control, and Computing, Allerton 2016 |

Publisher | Institute of Electrical and Electronics Engineers Inc. |

Pages | 1142-1148 |

Number of pages | 7 |

ISBN (Electronic) | 9781509045495 |

DOIs | |

State | Published - Feb 10 2017 |

Event | 54th Annual Allerton Conference on Communication, Control, and Computing, Allerton 2016 - Monticello, United States Duration: Sep 27 2016 → Sep 30 2016 |

### Other

Other | 54th Annual Allerton Conference on Communication, Control, and Computing, Allerton 2016 |
---|---|

Country | United States |

City | Monticello |

Period | 9/27/16 → 9/30/16 |

### Fingerprint

### Keywords

- Asymptotic analysis
- Asynchronous algorithms
- Clock synchronization
- Collusion attacks
- Cyberphysical systems
- Cybersecurity
- Distributed systems
- Fundamental limits
- Wireless sensor networks

### ASJC Scopus subject areas

- Artificial Intelligence
- Computational Theory and Mathematics
- Computer Networks and Communications
- Hardware and Architecture
- Control and Optimization

### Cite this

*54th Annual Allerton Conference on Communication, Control, and Computing, Allerton 2016*(pp. 1142-1148). [7852364] Institute of Electrical and Electronics Engineers Inc.. https://doi.org/10.1109/ALLERTON.2016.7852364

**Secure clock synchronization under collusion attacks.** / Duan, Xiaoming; Freris, Nikolaos; Cheng, Peng.

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

*54th Annual Allerton Conference on Communication, Control, and Computing, Allerton 2016.*, 7852364, Institute of Electrical and Electronics Engineers Inc., pp. 1142-1148, 54th Annual Allerton Conference on Communication, Control, and Computing, Allerton 2016, Monticello, United States, 9/27/16. https://doi.org/10.1109/ALLERTON.2016.7852364

}

TY - GEN

T1 - Secure clock synchronization under collusion attacks

AU - Duan, Xiaoming

AU - Freris, Nikolaos

AU - Cheng, Peng

PY - 2017/2/10

Y1 - 2017/2/10

N2 - Recently, the Secure Average Time Synchronization (SATS) protocol has been proposed and analyzed; this distributed clock synchronization protocol is capable of successfully tackling several attacks such as denial-of-service (DoS), message-delay, message duplication/repetition, and even a generic message manipulation. However, the collusion attack, in which neighboring malicious nodes may cooperate so as to strike stealthier attacks that are more difficult to handle, remains by and large an open problem. In the setup of SATS, we derive the fundamental asymptotic bounds in the number of malicious agents-as function of the benign ones-that can be efficiently handled without tampering accurate network-wide synchronization. Going a step further, we develop a risk model for collusions and use it to obtain even tighter bounds. In specific, we establish that SATS can handle 'many' malicious nodes with high probability: an order of almost square-root of the benign ones for the case of no risk, and almost linear when the risk of collusion is accounted. Last but not least, we analyze and experimentally assess an interesting phenomenon: the presence of attackers may lead to a convergence speedup of SATS, since malicious nodes can be effectively constrained from the network, thus affecting the algebraic connectivity of the graph corresponding to the network topology. Numerical simulations verify the theoretical results, i.e., collusions are avoided when the number of malicious nodes is bounded by the asymptotic bounds and the algebraic connectivity increases due to incorporating 'well behaved' malicious nodes.

AB - Recently, the Secure Average Time Synchronization (SATS) protocol has been proposed and analyzed; this distributed clock synchronization protocol is capable of successfully tackling several attacks such as denial-of-service (DoS), message-delay, message duplication/repetition, and even a generic message manipulation. However, the collusion attack, in which neighboring malicious nodes may cooperate so as to strike stealthier attacks that are more difficult to handle, remains by and large an open problem. In the setup of SATS, we derive the fundamental asymptotic bounds in the number of malicious agents-as function of the benign ones-that can be efficiently handled without tampering accurate network-wide synchronization. Going a step further, we develop a risk model for collusions and use it to obtain even tighter bounds. In specific, we establish that SATS can handle 'many' malicious nodes with high probability: an order of almost square-root of the benign ones for the case of no risk, and almost linear when the risk of collusion is accounted. Last but not least, we analyze and experimentally assess an interesting phenomenon: the presence of attackers may lead to a convergence speedup of SATS, since malicious nodes can be effectively constrained from the network, thus affecting the algebraic connectivity of the graph corresponding to the network topology. Numerical simulations verify the theoretical results, i.e., collusions are avoided when the number of malicious nodes is bounded by the asymptotic bounds and the algebraic connectivity increases due to incorporating 'well behaved' malicious nodes.

KW - Asymptotic analysis

KW - Asynchronous algorithms

KW - Clock synchronization

KW - Collusion attacks

KW - Cyberphysical systems

KW - Cybersecurity

KW - Distributed systems

KW - Fundamental limits

KW - Wireless sensor networks

UR - http://www.scopus.com/inward/record.url?scp=85015180476&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85015180476&partnerID=8YFLogxK

U2 - 10.1109/ALLERTON.2016.7852364

DO - 10.1109/ALLERTON.2016.7852364

M3 - Conference contribution

SP - 1142

EP - 1148

BT - 54th Annual Allerton Conference on Communication, Control, and Computing, Allerton 2016

PB - Institute of Electrical and Electronics Engineers Inc.

ER -