Welcome to my GitHub portfolio. I am an experienced engineer specializing in cybersecurity, cryptography, and distributed systems. With a strong foundation in applied mathematics and low-level programming, I focus on building secure, high-performance systems and developing advanced cryptographic solutions.

• Distributed Systems: Designed and optimized systems handling over 1 million requests per second. Expertise in ensuring high-performance and secure operations with Rust and C++.
• Cryptography: Proficient in cryptographic protocols, including AES, RSA, ECC, and post-quantum cryptography. Focused on securing blockchain networks and distributed systems.
• Low-Level Programming: Advanced skills in Rust, C++, C, and Python. Specialize in optimizing mission-critical systems for security and efficiency.
• Backend Development: Expertise in Rust-based backend systems, including microservices architecture and legacy system migration.

OpenZeppelin, Remote (Dec 2023 – Jun 2024, Now Contributor)

• Conducted security analyses of zero-knowledge proof systems, identifying and mitigating vulnerabilities.
• Engineered cryptographic components in Rust, Go, and Solidity to enhance blockchain application security.
• Audited Ethereum-based smart contracts, optimizing them for cryptographic robustness and gas efficiency.
• Advanced research in cryptographic primitives such as roots of unity and elliptic curves.

SecureTech Solutions GmbH, Remote, Austria (Aug 2023 – Apr 2024)

• Led cryptographic audits to identify vulnerabilities, maintaining a zero-security-breach record for two years.
• Developed secure key management solutions, reducing key compromise incidents by 40%.
• Optimized assembly-level encryption routines for ARM and x86 architectures, improving performance.

NextGen Technologies, Remote, Italy (Jul 2022 – Jul 2023)

• Designed distributed systems managing over 1 million requests per second.
• Implemented cryptographic solutions for blockchain applications, reducing processing delays by 15%.
• Enhanced security testing for performance-critical modules, improving system security by 20%.

InnovateTech Italy, Hybrid, Italy (Jan 2022 – Jun 2022)

• Migrated legacy systems to Rust, resolving vulnerabilities and improving security posture.
• Conducted threat modeling and applied low-level optimizations to enhance resilience and efficiency.

TechSolutions UA, Hybrid, Ukraine (Jan 2021 – Dec 2021)

• Delivered high-performance systems for enterprise clients, increasing security by 22%.
• Advised on integrating cryptographic protocols into distributed systems to mitigate risks.

TechSolutions UA, On-Site, Ukraine (Oct 2019 – Dec 2020)

• Built secure web servers handling high request loads, using asynchronous programming.
• Contributed to optimizing real-time network operations.

• Master of Science in Applied Mathematics
  Lviv Polytechnic National University (2020–2022)
  Thesis: Mathematical Modeling of Cryptographic Protocols for Secure Distributed Systems.

• Master of Science in Information Systems and Technologies
  Odessa National Polytechnic University (2019–2020)
  Thesis: Implementation of Post-Quantum Cryptography in Secure Data Management Systems.

• Quantum Cryptographic Toolkit
  Developed tools for post-quantum cryptography, enhancing system resistance to quantum attacks by 40%.

• Optimization of Consensus Protocols
  Improved scalability and resilience of distributed systems by optimizing cryptographic consensus protocols.

• Blockchain Security Enhancements
  Designed cryptographic modules that reduced vulnerabilities in distributed blockchain networks.

• Cryptographic Security in Blockchain and Distributed Systems
• Post-Quantum Cryptography for Cybersecurity Applications
• High-Performance Computing in Cryptography
• Optimization of Consensus Mechanisms in Decentralized Networks
• Threat Mitigation in High-Performance Systems

• Krizhanovskyi, D. "Mathematical Modeling of Consensus Protocols for Distributed Systems." SSRN (2024).
• Krizhanovskyi, D. "Comparative Analysis of Post-Quantum Cryptographic Algorithms for Distributed Systems." viXra (2023).

• LinkedIn: Daniil Krizhanovskyi
• Email: daniil.krizhanovskyi@hotmail.com
• GitHub: dkrizhanovskyi

Thank you for visiting my GitHub portfolio. I am open to collaborations in cryptography, distributed systems, and high-performance computing.