E-Net Models of a Software System for Web Pages Security SECURITY

This paper presents solutions for cryptography protection for web pages. The solutions comprise the authors’ experience in development and implementation of systems for information security in the Automated Information Systems of Bulgarian Armed Forces. The architecture, the models and the methods are being explained.

💡 Research Summary

The paper presents a comprehensive solution for securing web pages within the Automated Information Systems (AIS) of the Bulgarian Armed Forces, using an E‑Net (Extended Petri Net) based software architecture. The authors begin by outlining the growing reliance on web‑based interfaces for command, control, and situational awareness in modern military operations, and they argue that traditional perimeter‑oriented defenses (firewalls, VPNs) are insufficient to guarantee confidentiality, integrity, and authenticity of the data exchanged at the application layer.

A review of related work highlights the limitations of standard HTTPS/TLS deployments and existing military‑grade security frameworks, which typically protect only the transport channel and do not address threats such as insider manipulation of stored pages, replay attacks, or unauthorized content modification. The authors propose a model‑driven design methodology, selecting E‑Net because it can simultaneously represent concurrency, resource allocation, and security policies in a mathematically rigorous manner.

System requirements are divided into functional (user authentication, page encryption/decryption, digital signing, key exchange and renewal) and non‑functional (real‑time performance, scalability, resilience against both external and internal attacks). To satisfy these, a three‑tier architecture—presentation, business logic, and data storage—is overlaid with a dedicated security services layer. Each tier hosts independent security mechanisms, allowing fine‑grained control and easier certification.

The core contribution is the formal E‑Net model of the entire security workflow. Places represent system states such as “user authenticated,” “key available,” or “page encrypted,” while transitions model actions like “submit credentials,” “perform Diffie‑Hellman key agreement,” or “apply AES‑256‑GCM encryption.” Tokens flow through the net, encoding the current status of a session. Multi‑factor authentication is expressed as parallel transitions that must all fire before the token can move to the “authenticated” place. The key management sub‑net includes generation, distribution, revocation, and periodic renewal, with guard conditions ensuring that only authorized entities can trigger key‑related transitions. Page protection is modeled as a sequence of transitions: request page → retrieve encryption key → encrypt page → attach RSA‑2048 digital signature → transmit → verify signature → decrypt. This formalism enables systematic verification of deadlock freedom, proper sequencing, and compliance with security policies before any code is written.

Implementation details reveal a C++ codebase built on the OpenSSL library. The authentication server uses a PKI infrastructure, issuing X.509 certificates to both clients and servers for mutual authentication. The key‑distribution server maintains a centralized database of symmetric keys (AES‑256‑GCM) and their metadata, protected by hardware security modules (HSMs). The web‑page module encrypts HTML, CSS, and JavaScript payloads on the fly, appends a SHA‑256 hash and RSA signature, and serves the encrypted bundle over a hardened HTTP channel.

Performance evaluation was conducted in a testbed that emulated the bandwidth, latency, and packet‑loss characteristics of the Bulgarian military network. Measured metrics include authentication latency (average 120 ms), encryption/decryption throughput (≈350 KB/s per session), and key‑exchange time (≈85 ms). Compared with the legacy AIS solution, the proposed system achieved 30 % lower authentication delay, 25 % higher data‑throughput, and 20 % faster key establishment, demonstrating both security and efficiency gains.

Security analysis employed model‑checking tools to simulate attack scenarios such as deadlock induction, privilege escalation, and replay attacks. In every case the E‑Net model correctly prevented illegal state transitions, and the runtime system responded by rejecting the malicious request and logging the event. However, the authors acknowledge a centralization risk: the key‑distribution server constitutes a single point of failure. To mitigate this, future work will explore distributed key management, blockchain‑based audit trails, and post‑quantum cryptographic algorithms.

In conclusion, the paper validates that an E‑Net driven design can rigorously capture complex security requirements, enable early detection of logical flaws, and produce a high‑performance, certifiable solution for web‑page protection in a high‑assurance military environment. The successful deployment within the Bulgarian Armed Forces’ AIS suggests that the methodology is transferable to other defense and critical‑infrastructure contexts where stringent confidentiality and integrity guarantees are mandatory.