International Journal
on Marine Navigation
and Safety of Sea Transportation
Volume 2
Number 1
March 2008
Smart Container Security the E-seal with RFID
Jin Zhang, Ya-qing Liu, Chun-yan Yu & Cui-fen Zhang
Dalian Maritime University, Dalian, China
ABSTRACT: In order to protect cargo from damage, theft, and terrorist threats, business and government turn
to wireless sensors and RFID tags, and tradition container is replaced by smart container. In this paper, the
basic technical features of RFID systems are described and linked to the practical applications. This paper will
also determine how the technologies perform in the real-world operational environments and evaluate the
various trade-offs that exist with E-seal design.
Cargo seals are more common in international trade
than for domestic shipments. This reflects the
historical and continuing importance of Customs
duties and cross-border smuggling. Manual cargo
seals have long been part of good security practice.
Their principal purpose is to assure carriers,
beneficial owners of cargo.
Manual seals vary widely in the degree of
protection they offer. Many factors affect protection,
including the design, materials, and construction of
the locking device, and the design and materials in
the hasp, bolt, or cable. The trade abounds with tales
of popular manual seal designs that have been
copied with cheap materials. There are no
international standards for manual seals.
Good seal practices improve the odds but cannot
guarantee shipment integrity. Clever miscreants can
defeat seals in numerous ways, such as cutting holes
in the side or top of a container and then repairing it.
However, the effectiveness of seal programs seems
more affected by poor practices than by unusually
skillful criminals.
Cargo container with smart systems alters globe
network in real time about security beaches. The
smart system is open, flexible and modular in
design. This will enable users to configure other
sensors or automatic identification technologies in
combinations applicable to their security or cargo
management needs. Other container sensors can
include hazardous chemical detection and various
physical parameters including temperature, light,
vibration, shock, atmospheric pressure and so on.
E-seal ensure that ever-increasing cargo loads also
have far greater protection. These seals, combining
robust mechanical parts with sophisticated sensors,
deliver a highly cost-effective solution for the cargo
industry. An E-Seal is a radio frequency device that
transmits container information as it passes a reader
device, and issues alerts and error conditions if the
container has been tampered with or damaged. E-
Seals serve both commercial and security interests
by tracking commercial container shipments from
their point of origin, while en route, and to their final
destination and point of customs clearance.
3.1 E-seal technology
E-seals marry manual seal elements with electronic
components to measure seal integrity, store data,
and provide communications. Some designs use
infrared signals and others use direct contact
communications technologies, but radio frequency
identification (RFID) is the most common choice.
Most e-seal designs automate the essential functions
of seal checking and reporting in order to remove
human intervention [1].
RFID has long been touted as the future of
logistics for all companies by allowing retailers and
suppliers to track goods throughout the supply chain.
Global logistics company Schenker is testing the use
of radio frequency identification (RFID) technology
to track containers used for overseas shipments.
RFID is the system technology that recognizes a
human or material by radio information communica-
tion and writes additional information through the
media of a card/tag that is built-in IC chip or
resonance material.
Fig. 1. RFID seal
4.1 System configuration
The purpose of the system is to communicate
data between informational medium (that is called
“RF tag”, “Transponder” of the shape of the
card/tag) and an interrogator (that is called “Reader”,
“Interrogator”) by the electric wave.
4.2 Features and Classification
Recognizable from a distance; Recognizable through
an obstacle; Reading two or more tags
simultaneously is possible; Writing additional
information is also possible; RF tag is reusable.
There are two main types of RFID tags and seals,
passive and active.
Passive seals do not initiate transmissions-they
respond when activated by the energy in the signal
from a reader. Interrogated by a reader, a passive
seal can identify itself by reporting its “license plate
number, analogous to a standard bar code. The tag
can also perform processes, such as testing the
integrity of a seal. The beauty of a battery-free
passive seal is that it can be a simple, inexpensive,
and disposable device. Passive RFID seals can
carry batteries for either or both of two purposes.
The first is to aid communication by boosting the
strength of the reflective signal back to the reader.
This capability need not add much cost. The second
purpose is to provide power so functions can be
performed out of the range of readers [2].
Active seals can initiate transmissions as well as
respond to interrogation. All active tags and seals
require on-board power, which generally means a
All active RFID electronic seals on or
approaching the market monitor seal integrity on a
near- -continuous basis, and most capture the time
of tampering and write it to an on-board log. Some
can accept GPS and sensor inputs, and some
can provide live “mayday” tampering reports as the
events happen, mostly within specially equipped
Passive vs active RFID seals. One may look at the
trade-offs between these technologies from
theoretical and practical perspectives. Theoretically,
the only difference between passive and active tags
and seals is the ability to initiate communications
from the tag-distinction that means passive RFID
tags could not initiate mayday calls. However, a
designer could add on-board power to a passive tag,
match other functionality and, setting aside
regulatory, safety, and cost issues, increase read
range and directional flexibility by increasing power
and adding antennas.
4.3 Standards and Frequencies [3], [4]
Adoption of RFID in supply chain and security
applications is hampered by a lack of standards and
by what some call “the frequency wars”. The two
issues are interrelated.Standards for electronic
seals address technical protocols, interfaces, and
frequencies. There are three related items.
ISO 10374 is the existing voluntary standard for
RFID automatic identification of freight
containers. It is a dual frequency passive read- -
only standard that includes 850-950 and 2400-
2500 MHz. Globally, only two carriers use these
tags, one primarily on chassis and the other on
chassis, ocean containers, and many dray trucks.
ISO 18185 is a Draft International Standard for
electronic container seals. It includes passive and
active protocols, enabling both simple low cost
and more robust seals. The active protocols have
been the focal point for “the frequency wars”
in terms of freight containers.
ISO 23359 is a New Work Item for read/write
RFID for freight containers. Work started on this
project in June 2002, and it seems likely to build
closely on the draft seal standard.
Frequency choice begins with technical
performance but includes political and regulatory
issues. In crowded freight-oriented environments
such as warehouses and terminals, the most effective
frequencies appear to be between 100 and 1000
MHz. Frequencies below 100 MHz lose range
rapidly because of inductive coupling or noise from
electrical coupling. Frequencies above 1000 MHz,
with shorter wavelengths, cannot wrap or diffract
around objects such as vehicles and freight
containers-they become more line-of-sight and
subject to blind spots.
Container shipping is a critical component of global
trade: about 90% of global trade is transported in
cargo containers. Globalization and market
deregulation have also led to advances in security
devices and instruments and their strategic
integration within the logistics sector. The market
for E-seal that may improve both freight
transportation security and productivity is in its early
stages. We will become a big winner of market in
development through relatively early stages of use.
1. Le-Pong Chin Chia-Lin Wu; The Role of Electronic
Container Seal (E-Seal) with RFID Technology in the
Container Security Initiatives”; MEMS, NANO and Smart
Systems, 2004. ICMENS 2004. Proceedings. 2004
International Conference on Aug. 2004, P116-120.
2. HU JianyunHE YanMIN Hao; “Design and Analysis
of Analog Front-End of Passive RFID Transponders”;
Vol. 27, No. 6, P.999-1005.
3. International standard ISO/IEC 14443-1,-2,-3, International
Standardization Organization, April 2003.
4. Jung-Hyun Cho, et; An analog front-end IP for 13.56 MHz
RFID interrogators”; Proceedings of the 2005 conference
on Asia South Pacific design automation 2005, p. 1208- -