Underwater Acoustic Communication Security Team 185. Sponsor: Prof. Shengli Zhou

Transcription

1 Underwater Acoustic Communication Security Team 185 Sponsor: Prof. Shengli Zhou

2 Outline Modems and Modulation types AquaSent (OFDM) Benthos(FSK) EvoLogics (S2C) Linkquest (DSSS) UAN physical layer security Types of jammers Types of Attack Jamming setup Project Specification Project Schedule

3 AquaSeNT OFDM

4 Multiplexing: OFDM OFDM may use either PSK or QAM modulation An example of a parallel transmission system. Each sub carrier only occupies a small portion of total bandwidth Has the advantage of reducing frequency selective channel fading by employing frequency diversity. OFDM suffers less from cross talk than an FDM system would OFDM requires strict signal synchronization.

5 OFDM: Advantages 3x to 10x greater data transmission rates; possibly higher over short ranges Insensitive to multipath: echoes, reflected signals that arrive with a delay time Benefits to the user More robust communication link: fewer errors or severed links 3x 10x increase in quantity of data in an application Multi-node networks are now possible: Assets over an area of the sea floor can be wirelessly networked together Signal hopping networks can transmit data over long ranges

6 OFDM: Current Uses IEEE a, g, n and HIPERLAN/2. The wireless personal area network (PAN) ultrawideband (UWB) IEEE a implementation Used in several 4G and pre-4g cellular networks and mobile broadband standards: The mobility mode of the wireless MAN/broadband wireless access (BWA) standard IEEE e (or Mobile-WiMAX). The mobile broadband wireless access (MBWA) standard IEEE the downlink of the 3GPP Long Term Evolution (LTE) fourth generation mobile broadband standard. The radio interface was formerly named High Speed OFDM Packet Access (HSOPA), now named Evolved UMTS Terrestrial Radio Access (E-UTRA). Underwater Acoustic Communications

7 AquaSeNT Background Aquatic Sensor Network Technology (AquaSeNT) has pioneered orthogonal frequency division multiplexing (OFDM) technology for subsea communication. AquaSeNT s OFDM technology has the capacity to deliver more information using a narrower bandwidth than competing technologies. Founders: Dr. Jun-Hong Cui - networking theory Dr. Shengli Zhou- digital signal processing Dr. Jerry Shi - low power, embedded system design

8 AquaSeNT Technology & Product Development Status 8 years of technology / concept development (academic & commercial research) Core technology is patented; 2 additional patents pending Thousands of hours of lab and lake tests Prototype testing, Fall, Validated 3100 bps / 5 km range / horizontal communication channel - High multipath environment where other systems fail 6 months continuous service, Chesapeake Bay NOAA application Commercial launch: October 2012 AquaSeNT technology: adapted OFDM modulation techniques from WIFI and the telecommunications industry to underwater communication; data is transmitted in parallel, not in series, delivering significant benefits to the user

9 Benthos Frequency- Shift Keying (FSK) Underwater Acoustic Communication

10 Benthos Background Founded: 1962 by Samuel O. Raymond in North Falmouth, Mass. During the first thirty years: focused on supplying underwater equipment to military and government markets esp. the scientific community 2006: Acquired by Teledyne Technologies Incorporated (Now known as Teledyne Benthos)

11 History Highlights 1985 Benthos imaging and acoustic equipment used by Woods Hole Oceanographic Institution team to discover the remains of the Titanic 1989 Benthos deep sea cameras were used by a team led by Dr. Robert Ballard to capture images of the German WWII battleship Bismarck Bismarck Wreckage First sent from a submarine traveling at speed and depth was sent to the surface using Benthos modems

12 Teledyne Benthos Underwater Acoustic Modems Used around the world to transmit data wirelessly in underwater applications. ATM-885 Acoustic Telemetry Modem Benefits include: Cost saving over expensive underwater cabling Extending the reach of cabled networks (by using a set of sensor nodes that can transfer data back to the cabled networks) Variety of modems available rated for different depths and operation in both shallow or deep water

13 Wireless Underwater Communications System Modems provide wireless bidirectional communication between a local host and a remote host Local/remote hosts connect to the local/ remote modems respectively over serial interfaces Wireless Underwater Communication System Block Diagram Both local modems will be ATM-885 Series Local and remote hosts can also both be PCs or instruments

14 General Types of Communication 1) Commands Output by the local host processor to the local modem over the serial interface Executed either by this modem or transmitted over the acoustic link to be executed by the remote modem 2) Data Output either by the local host processor to the local modem, the reverse respectively, or both Exchanged freely and bidirectionally between the two hosts over the acoustic link The operating mode of the modem determines the type of communication

15 Modulation Techniques Phase Shift Keying (PSK) Allows modems to operate at up to 15,360 bits/sec High bandwidth efficiency Primarily used when multipath interference is at a minimum ATM-885 Module can transmit data using PSK, but receives data using MFSK only Multiple Frequency Shift Keying (MFSK) Spread spectrum modulation process that transmits multiple tones simultaneously Maximum bit rate of 2400 bits/sec. Reliability even in a high multipath environment

16 Methods for Increasing Reliability Convolutional Coding Uses error correcting algorithms determined from the data being transmitted Most effective for increasing reliability Multipath Guard Period Used only with MFSK modulation Provides a short delay between data frames, allowing for the dispersion of multipath signals Data Redundancy (AKA frequency diversity) Repeats the transmission of a series of data bits

17 S2C Technology Sweep Spread Carrier Technology

18 Sweep Spread Carrier Technology

19 Behind the Technology S2C = Sweep Spread Carrier Technology Hydro-acoustics communications mimic dolphin s sound pattern dolphins chirp and sing across broad frequency bandwidths This technology spreads the signal energy over a wide range of frequencies and adapt the signal structure so that multipath components don t interfere with each other

20 Behind the Technology At the receiver end, advanced signal processing collects the energy and converts the signals into narrow band signals This achieves significant depression of disturbances and substantial system gain Enables successful decoding of signals in crucial environments even when the environments are heavily masked by noise

21 Background Evologics is a German company founded in 2000 by leading international scientists They work to develop innovative key technologies for the aerospace, maritime, and offshore industries through engineering and life sciences Improving engineering by learning from nature

22 R-Series Underwater Acoustic Modems

23 Configuration Options Housing: Derlin (high-grade plastic), aluminum-magnesium alloy, stainless steel Interface: RS-232 (RS-485 optional) and/or Ethernet Wake Up Module to save battery power Wakes up device only when needed External power supply or internal rechargeable battery pack

24 Reasons to choose S2C When implementing an acoustic underwater communication system, multipath propagation of acoustic waves is the biggest challenge Path delays that are larger than the period lengths of the signals involved are the result of sound traveling at 1500 m/s in water (Propagation multiplication or increase) (Multipath propagation production of more paths) Additional signal processing must be used to actually gain phase info out of the different path signals adding up at the receiver hydrophone

25 Fighting Multipath Propagation Consequences of S2C modulated signal arriving at the receiver: It is presumed that all transmitter-receiver paths have their own path delays and sweep time is larger than the channel delay spread. Sweep time is larger than the delay difference between the longest and shortest paths Because of this, every signal arriving at the receiver is located on its own instant frequency It is then possible to identify the different path arrivals in the frequency domain

26 Fighting Multipath Propagation Despreading of the received signal: Using the S2C carrier synchronized on the transmitter-receiver path containing the most energy (main multipath) instead of the constant frequency carrier to get the baseband representation of the received signal Problems: Signal is heavily distorted by different multipath so it is crucial to filter out all distorting path arrivals before you can estimate the transmitted symbol using a matched filter

27 Multipath to single path systems S2C is used to fix the problems encountered when fighting multipath propagation. (distortion) It transforms the communication system from a multipath system to a single path system Every multipath arrival has its own frequency sweep at the receiver. After despreading, the sweeps disappear and different arrivals are now on their own constant frequency with the main multipath arrival situated at 0Hz. Applying a lowpass filter with a cutoff frequency, it is now possible to filter out all distorting multipaths, which isolates the main energy arrival.

28 DSP Comm : AquaComm Modem

29 High Reliability of Communications Designed for highly reliable underwater communications Works in virtually any real world sea state where others have failed Dramatically reduces operational risks and maintenance costs Major organizations have tested and proven the reliability of this modem through commercial use Brings certainty and confidence that your application will work

30 Low Power Consumption This modem uses times less power than competing modems Lower maintenance requirements and total cost of ownership Broadens the applications the modem can be used for Small Form and Lightweight Less than half the size of competing modems Broadens the types of applications the modem can be used for

31 Ease of Integration Small form factor, lightweight Quick and low-cost integration Transparent command modes Lower total cost of ownership Command structure that is easy to understand Can quickly and successfully integrate with numerous products

32 Small Form and Lightweight Less than half the size of competing modems Broadens the types of applications the modem can be used for

33 Specs

34 Linkquest: Direct Sequence Spread Spectrum (DSSS)

35 Introduction

36 History In 1941, Hollywood actress Hedy Lamarr and pianist George Antheil described a secure radio link to control torpedoes and received U.S. patent # In 1981, U.S. Army started using this technology and has become increasingly popular for applications that involve radio links in hostile environments.

37 Process

38 Benefits Resistance to intended or unintended jamming Sharing of a single channel among multiple Reduced signal noise level Uses GPS (Navigation Systems) DS-CDMA (Verizon, Sprint) IEEE (Wi-Fi) Radio-Controlled model Vehicles

39 Modem used for the Project

40 UAN Physical Layer Security

41 Challenges to UAN Security Long Propagation Delays Narrow Bandwidth Mutlipath Effects Cannot directly apply existing terrestrial security schemes to UAN s (Underwater Acoustic Networks) Difficult to model an aqueous environment accurately [1] Michael Zuba, Zhijie Shi, Zheng Peng, Jun-Hong Cui, Shengli Zhou, Vulnerabilities of underwater acoustic networks to denial-of-service jaming attacks, Security and Communication Networks DOI: /sec.507 ed., Wiley Online Library, 2012.

42 UAN Threats attacks 3. Threats, attacks andand defenses in U defenses Figure1. Security issues, attacks and defenses [3] Yanping Cong, Guang Yang, Zhiqiang Wei, Wei Zhou, Security in Underwater Sensor Network, College of Information Science and Engineering ed., Qingdao, China: Ocean University of China, 2010.

43 Types of Attack Denial of Service (DoS) Attack Dummy (signal) Jammer Smart (Deceptive) Attack [1] Michael Zuba, Zhijie Shi, Zheng Peng, Jun-Hong Cui, Shengli Zhou, Vulnerabilities of underwater acoustic networks to denial-of-service jaming attacks, Security and Communication Networks DOI: /sec.507 ed., Wiley Online Library, 2012.

44 Dummy (Signal) Attack Knows nothing about the protocols of the network Generates noise to corrupt packets UAN s exist in an open environment and are particularly vulnerable. [1] Michael Zuba, Zhijie Shi, Zheng Peng, Jun-Hong Cui, Shengli Zhou, Vulnerabilities of underwater acoustic networks to denial-of-service jaming attacks, Security and Communication Networks DOI: /sec.507 ed., Wiley Online Library, 2012.

45 Smart (Deceptive) Attack Knows some information about the network protocols Generally does not follow the MAC (medium access control protocol) Uses legitimate control or data packets to corrupt the channel This type of jammer will pretend to be a legitimate node. [1] Michael Zuba, Zhijie Shi, Zheng Peng, Jun-Hong Cui, Shengli Zhou, Vulnerabilities of underwater acoustic networks to denial-of-service jaming attacks, Security and Communication Networks DOI: /sec.507 ed., Wiley Online Library, 2012.

46 Modes of Attack Constant Attack Continually injects signals (noise or regular packets) into the communications channel. Random Attack Will alternate between attacking and sleeping in a pseudorandom fashion. Reactive Attack When network activity is sensed the jammer will start attempting to jam the network. This is considered to be more advanced. [1] Michael Zuba, Zhijie Shi, Zheng Peng, Jun-Hong Cui, Shengli Zhou, Vulnerabilities of underwater acoustic networks to denial-of-service jaming attacks, Security and Communication Networks DOI: /sec.507 ed., Wiley Online Library, 2012.

47 Jammer ITC 1032 with a 12V supply [1] Michael Zuba, Zhijie Shi, Zheng Peng, Jun-Hong Cui, Shengli Zhou, Vulnerabilities of underwater acoustic networks to denial-of-service jaming attacks, Security and Communication Networks DOI: /sec.507 ed., Wiley Online Library, 2012.

48 Type Projector/Hydrophone Resonance Frequency f r 33 khz Depth 1250 meters Envelope Dimensions (in.) 2.7D TVR at f r 149 db//µpa/v@1m Midband OCV -194 db//1v/µpa Suggested Band khz Beam Type Spherical Input Power 800 watts

49 Initial testing Setup Signal Coordination Transmit Receive Jamm Acoustic Modem ITC-1032

50 Effective Jamming Preamble is the most effective attacking point Effective scheme requires three phases: Detection of transmission (1) Starting jamming transmission (2) Period of jamming transmission (3) Signal Propagation Time (4) Preamble [1] Michael Zuba, Zhijie Shi, Zheng Peng, Jun-Hong Cui, Shengli Zhou, Vulnerabilities of underwater acoustic networks to denial-of-service jaming attacks, Security and Communication Networks DOI: /sec.507 ed., Wiley Online Library, 2012.

51 Team 185 Schedule

52 2013 IMPORTANT)DATES School&Event& JULY AUGUST Design&Deliverible M T W T F S S M T W T F S S Team&Meeting @Aug First&day&of&Class @Sep Last&day&to&drop&without&W @Sep Project-Statement-Due @Sep Project-Specfication-Due 9@Oct Presentation 11@Oct First&Tank&test/Lab&Familiarization& SEPTEMBER OCTOBER 25@Oct Last&Pool&Test M T W T F S S M T W T F S S 28@Oct Last&day&to&drop&a&course @Oct Project-Proposal-Due @Nov First&Pool&Test @Nov Last&Pool&Test @Nov Thankgiving&Break @Nov End&Thanksgiving&Break 30 9@Dec Final-Report-Due!!! 9@Dec Final&Exams NOVEMBER DECEMBER 15@Dec End&Final&Exams M T W T F S S M T W T F S S Team& Meet&every&Friday&12:

53 Project Specifications Team 185 Project Specification on Google Docs