eSSP – Secure Protocol for Toll Collection Systems

With the development of cash payment automation, especially in the vending, entertainment and self-service sectors, there is a growing need for transaction security at the highest level. eSSP (Encrypted Smiley Secure Protocol) is an advanced encryption protocol developed by Innovative Technology that meets the needs for secure data exchange between the banknote-accepting device and the host machine. Thanks to eSSP, system integrators gain confidence that their solutions are resistant to manipulation and data eavesdropping, while providing full control over devices.

Why is eSSP so important? Unlike many older communication protocols, eSSP offers end-to-end encryption and device verification, which minimizes the risk of fraud and other threats. In this article, we will discuss the key aspects of the eSSP protocol, its operation, and the benefits it brings to toll systems.

How does the eSSP protocol work?

The eSSP protocol is based on the master-slave model, in which the main controller is a host machine (e.g. a vending machine) and the dependent devices are different peripherals such as banknote readers, coins or hoppers. The host, as a master, manages the data exchange process, while peripherals act as slaves by executing commands. Data is transmitted asynchronously via a multiple access bus, which allows simultaneous support of several devices, and at the same time ensures the consistency and security of transmission thanks to the use of special open-collector drivers.

The security of eSSP communication is enhanced by the use of 128-bit encryption, which provides reliable protection against unauthorized access attempts. The key is divided into two parts: the lower part, 64-bit, is set by the machine manufacturer, which gives control over access to the devices, while the upper 64 bits are dynamically negotiated each time the system is started. Thanks to this, each communication session uses a unique key, which makes it much more difficult to capture data.

Benefits of eSSP for payment system integrators

Thanks to eSSP, payment system integrators can count on comprehensive protection against a number of threats that may occur in cash register systems and vending machines. Here are the key benefits:

• Protection against manipulation and eavesdropping: The eSSP protocol eliminates the risk of attempts to eavesdrop on transmission lines and manipulate acceptor settings. Thanks to full data encryption, information transmitted between the host and the device is secure and cannot be read by unauthorized persons.
• Device access control: Each device operating in the eSSP protocol has a unique serial number that allows it to be clearly identified and verified. The host checks the series before proceeding with the transaction, which prevents the acceptor or other device from being replaced in the machine without the operator’s knowledge.
• Elimination of the risk of device replacement and reprogramming: The protocol is resistant to attempts to replace devices and to unauthorized reprogramming of acceptors, which in the past posed a big threat to payment systems in machines. With an advanced verification model, each device must be registered and approved by the host before it starts working.

eSSP offers integrators the confidence that their systems are not only modern, but also resistant to increasingly sophisticated threats.

Security and algorithms used in eSSP

The eSSP protocol uses advanced encryption methods that are designed to protect data and eliminate the risk of interception or modification of information transmitted between the banknote acceptor and the host machine. The encryption key used in eSSP is 128 bits long and is divided into two parts:

• The lower part of the wrench (64 bits) is fixed and fixed by the machine manufacturer, which allows access control to the devices. Thanks to this, only authorized devices can work in the system.
• The upper part of the key (another 64 bits) is dynamically negotiated between the device and the host at each run, which ensures the uniqueness of the key for each communication session. This process uses the military approved AES (Advanced Encryption Standard) algorithm, which is one of the highest levels of security available.

An additional layer of protection is the use of 16-bit CRC checksums, which verify the integrity of the data in each packet sent. This solution minimizes the risk of transmission errors and ensures uninterrupted, stable communication. Data encryption and verification at the level offered by eSSP is the standard recommended in all new applications using cash systems.

Implementation in practice – SDK and tools for developers

For integrators and developers who want to implement eSSP in their projects, Innovative Technology has prepared sets of programming tools (SDK) that significantly facilitate the integration process. The SDK includes not only ready-made libraries for port handling, encryption key negotiation and package creation, but also source code examples.

Thanks to these resources, protocol implementation is possible even for people with limited programming experience. SDKs are compatible with popular development environments, including C# (. Net Framework), and soon also with C++ on Windows and Linux. In addition, the full documentation describing the implementation process provides support throughout the implementation process – from the basic configuration to advanced features.

The availability of support in the form of sample code and the possibility of easy access to additional documentation make the implementation of eSSP fast and avoids the typical difficulties associated with programming security and communication protocols. The use of eSSP not only shortens the integration time, but also minimizes the risk of errors at the implementation stage.

Application in vending systems

eSSP is already successfully used in many vending solutions, slot machines, self-service systems and other applications where the security of cash transactions is a priority. For example, in vending systems, eSSP prevents manipulations such as wiretapping transmissions or attempts to replace the banknote acceptor, which could lead to fraudulent transactions. Thanks to the encrypted connection, every transaction is secure, and the system operator has full control over the operation of devices on the network.

eSSP assures that vending machines that support cash payments are more resistant to hazards than traditional solutions. Integration with the eSSP system minimizes the losses associated with potential fraud attempts, which at the same time translates into greater trust in end users. In practice, every vending system with protocol implementation achieves a higher level of security, which promotes the development of cashless technologies and provides operators with peace of mind and operational stability.

eSSP vs other communication protocols (ccTalk, MDB, Pulse)

The eSSP protocol stands out from other commonly used communication protocols, such as ccTalk, MDB or Pulse, thanks to its advanced level of security and reliability of data transmission. Each of these protocols has its own application, but eSSP works best for applications that require a high level of data protection and full control over devices.

• ccTalk – It is a simple protocol used mainly in systems with low security requirements, used in machines and cassettes. Unlike eSSP, ccTalk does not have such a high level of encryption, which makes it more vulnerable to attacks.
• MDB (Multi-Drop Bus) – A protocol widely used in the vending industry, especially for communication with coin and banknote acceptors. Although MDB is a stable protocol, eSSP outperforms it in terms of security with 128-bit encryption.
• Pulse – This is a very basic protocol that does not offer any data security and is mainly used in simple vending devices. Pulse is based on sending pulses for each received banknote or coin, but the lack of encryption makes it completely unsuitable for systems where high transaction protection is required.

In conclusion, eSSP stands out from other protocols thanks to comprehensive data protection and is recommended wherever transaction security is crucial.

Why is it worth investing in eSSP?

eSSP is an excellent solution for payment system integrators who are looking for secure, modern solutions for managing cash transactions. With comprehensive encryption, tamper-resistant and full control over peripherals, eSSP sets a new standard for data protection. Using eSSP brings numerous benefits: from minimizing the risk of fraud to higher operational efficiency and lower costs of maintaining the payment infrastructure.

The investment allows integrators to provide the highest level of security and gain an advantage over the competition, which continues to use less advanced technologies. For operators, this means greater trust of users, and for integrators – confidence that the implemented solutions comply with the latest industry standards.

If you want to learn more about the possibilities of implementing the eSSP protocol or need technical support for the implementation of solutions based on this protocol, please contact our technical support department. The Innovative Technology team also offers access to SDKs and full documentation that allow you to quickly and smoothly implement the protocol in any payment application.

Do you have any questions or need additional information? Contact us and find out how eSSP can improve the security of your payment system.

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