Recent advances in quantum computing and Shor’s discovery of quantum algorithms that efficiently solve computational problems (integer factorization and discrete logarithm problems) form the basis of the Internet cryptographic infrastructure. It has fueled intensive research into the design and development of post-quantum (PQ) cryptographic systems that maintain their security when a quantum computer is built.We consider the PQ security of DTLS (Datagram Transport Layer Security), a communication security protocol that protects against eavesdropping, tampering, and packet forgery for datagrams. DTLS is the UDP counterpart of TLS (Transport Layer Security) and proposed to secure control messages in 5G networks. We offer a novel and efficient approach for providing secure source authentication and message integrity for DTLS that removes the need for a computationally expensive key exchange for message integrity by using PQ TESLA (Timed Efficient Stream Loss-tolerant Authentication) that relies on delayed key release mechanism to provide integrity and use a PQ hash-based signature for providing PQ source authentication. We analyze the security of our design, implement it in a widely used library called TinyDTLS, report the result of our experiments, and propose direction for future research.
Recent advances in quantum computing and Shor’s discovery of quantum algorithms that efficiently solve computational problems (integer factorization and discrete logarithm problems) form the basis of the Internet cryptographic infrastructure. It has fueled intensive research into the design and development of post-quantum (PQ) cryptographic systems that maintain their security when a quantum computer is built.We consider the PQ security of DTLS (Datagram Transport Layer Security), a communication security protocol that protects against eavesdropping, tampering, and packet forgery for datagrams. DTLS is the UDP counterpart of TLS (Transport Layer Security) and proposed to secure control messages in 5G networks. We offer a novel and efficient approach for providing secure source authentication and message integrity for DTLS that removes the need for a computationally expensive key exchange for message integrity by using PQ TESLA (Timed Efficient Stream Loss-tolerant Authentication) that relies on delayed key release mechanism to provide integrity and use a PQ hash-based signature for providing PQ source authentication. We analyze the security of our design, implement it in a widely used library called TinyDTLS, report the result of our experiments, and propose direction for future research.
All public-key cryptography algorithms that are in use today, including RSA (Rivest–Shamir- Adleman) cryptosystem, DSA (Digital Signature Algorithm), and DH (Diffie-Hellman) key agreement, will be broken if quantum computers become a reality. Hence, applications and protocols must be transitioned to quantum-resistant designs. We consider post-quantum security of DTLS (Datagram Transport Layer Security) for source authentication and message integrity. These are essential security requirements for control plane communications in 5G networks. To provide message integrity while avoiding costly post-quantum secure key exchange protocols that rely on unproven computational assumptions, we will use TESLA (Timed Efficient Stream Loss-tolerant Authentication) protocol. TESLA is a data stream authentication protocol that uses symmetric-key cryptographic primitives and a digital signature scheme to achieve security. We first replace the digital signature in TESLA with a hash-based one to achieve post-quantum security, and then carefully revise the DTLS handshake and record layer protocol to include the new TESLA protocol such that it delivers the same properties for DTLS. We argue our design’s security and show our model’s feasibility using an efficient implementation for an open-source DTLS library, called TinyDTLS. Finally, we provide performance measurements for PQ-DTLS compared with original DTLS in authentication and integrity only mode.
The potential of the swift development of quantum computing is an extreme danger to the traditional cryptographic programs, and they are the foundation of the modern communication infrastructure. RSA and ECC are classical public-key algorithms that can be successfully quantum-attacked, in particular, Shor's algorithm can easily factor large integers and calculate discrete logarithms (Bernstein et al., 2017). The Post-Quantum Cryptography (PQC) has become the key to secure the next-generation communication networks against these threats, which relies on lattice problem-based algorithms, hash-based based algorithms, multivariate polynomials-based algorithms, and code-based cryptography. The paper examines the concepts, design, and implementation issues of PQC within current network infrastructure focusing on the secure transmission of data, authentication, and key management in the upcoming 5G and 6G networks. The approach will include the survey of existing algorithms of PQC, model the integration of protocol in the communication systems and test computational efficiency, security strength, and scalability. It has been found that PQC is suitable to protect network communications against quantum attackers, and achieves reasonable performance, though trade-offs can be seen in terms of computation overhead, key size, and latency. The research offers understanding to the researcher, network engineers and policy makers in order to adopt quantum resistant cryptography protocols to secure the confidentiality, integrity and authenticity of information in the future communication networks.
Digital signatures are indispensable for security on the Internet, because they guarantee authenticity, integrity, and non-repudiation, of namely e-mails, software updates, and in the Transport Layer Security (TLS) protocol which is used for secure data transfer, for example. Most signature schemes that are currently in use such as the RSA signature scheme, are considered secure as long as the integer factorization problem or the discrete logarithm (DL) problem are computationally hard. At present, no algorithms have yet been found to solve these problems on conventional computers in polynomial time. However, in 1997, Shor published a polynomial-time algorithm that uses quantum computation to solve the integer factorization and the DL problem. In particular, this means that RSA signatures are considered broken as soon as large-scale quantum computers exist. Due to significant advances in the area of quantum computing, it is reasonable to assume that within 20 years, quantum computers that are able to break the RSA scheme, could exist. In order to maintain authenticity, integrity, and non-repudiation of data, cryptographic schemes that cannot be broken by quantum attacks are required. In addition, these so-called post-quantum secure schemes should be sufficiently efficient to be suitable for all established applications. Furthermore, solutions enabling a timely and secure transition from classical to post-quantum schemes are needed. This thesis contributes to the above-mentioned transition. In this thesis, we present the two lattice-based digital signature schemes TESLA and qTESLA, whereby lattice-based cryptography is one of five approaches to construct post-quantum secure schemes. Furthermore, we prove that our signature schemes are secure as long as the so-called Learning With Errors (LWE) problem is computationally hard to solve. It is presumed that even quantum computers cannot solve the LWE problem in polynomial time. The security of our schemes is proven using security reductions. Since our reductions are tight and explicit, efficient instantiations are possible that provably guarantee a selected security level, as long as the corresponding LWE instance provides a certain hardness level. Since both our reductions (as proven in the quantum random oracle model) and instantiations, take into account quantum attackers, TESLA and qTESLA are considered post-quantum secure. Concurrently, the run-times for generating and verifying signatures of qTESLA are similar (or faster) than those of the RSA scheme. However, key and signature sizes of RSA are smaller than those of qTESLA. In order to protect both the theoretical signature schemes and their implementations against attacks, we analyze possible vulnerabilities against implementation attacks. In particular, cache-side-channel attacks resulting from observing the cache behavior and fault attacks, which recover secret information by actively disrupting the execution of an algorithm are focused. We present effective countermeasures for each implementation attack we found. Our analyses and countermeasures also influence the design and implementation of qTESLA. Although our schemes are considered (post-quantum) secure according to state-of-the-art LWE attacks, cryptanalysis of lattice-based schemes is still a relatively new field of research in comparison to RSA schemes. Hence, there is a lack of confidence in the concrete instantiations and their promised security levels. However, due to developments within the field of quantum computers, a transition to post-quantum secure solutions seems to be more urgently required than ever. To solve this dilemma, we present an approach to combine two schemes, e.g., qTESLA and the RSA signature scheme, so that the combination is secure as long as one of the two combined schemes is secure. We present several of such combiners to construct hybrid signature schemes and hybrid key encapsulation mechanisms to ensure both authenticity and confidentiality in our Public-Key Infrastructure (PKI). Lastly, we also demonstrate how to apply the resulting hybrid schemes in standards such as X.509 or TLS. To summarize, this work presents post-quantum secure candidates which can, using our hybrid schemes, add post-quantum security to the current classical security in our PKI.
Shor's algorithm efficiently solves factoring and discrete logarithm problems using quantum computers, compromising all public key schemes used today. These schemes rely on assumptions on their computational complexity, which quantum computers can easily bypass. The solutions have to come from new algorithms - called Post-Quantum Cryptography (PQC) - or from new methods, such as Quantum Key Distribution (QKD). The former replicate the computational security ideas of classical public key algorithms, while the latter recurs to use the quantum properties of nature, which also brings a mathematical security proof, potentially offering Information-Theoretic Security. To secure data in the future, we must adopt these paradigms. With the speed of quantum computing advancements, the transition to quantum-safe cryptography within the next decade is critical. Delays could expose long-lived confidential data, as current encryption may be broken before its value expires. However, the shift must balance the adoption of new technologies with maintaining proven systems to protect against present and future threats. In this work, we have selected Transport Layer Security, one of the most widely used protocols, as the foundation to hybridize classical, quantum, and post-quantum cryptography in a way suitable for broad adoption in Software-Defined Networking, the most flexible networking paradigm that has been used to deploy integrated quantum-classical networks. To this end, we use standards for QKD key extraction and SDN integration. The purposed implementation is based on the latest version of TLS and demonstrates advanced capabilities such as rekeying and key transport across a large QKD network, while supporting crypto-agility and maintaining backward compatibility through the use of ciphersuites. The performance of this approach has been demonstrated using a deployed production infrastructure.
Cyber physical systems (CPSs) will be deployed for decades, thus they should be secure against long-term attacks. Most CPSs adopt the datagram transport layer security (DTLS), as the de facto security protocol. By using public key cryptography (PKC) based on traditional RSA or elliptic-curves, DTLS establishes secured communication channels between multiple parties. However, the foreseeable breakthrough of quantum computers represents a risk for many PKC ecosystems. Traditional PKC will no be longer considered secure. Therefore, the integration of post-quantum security is mandatory. Due to their limited resources, tight performance requirements, and long-term life-cycles, this is especially challenging for CPSs. In this letter we propose, implement and evaluate for the first time a post-quantum enhanced DTLS, able to establish secure communications of CPSs, even in the presence of quantum computers. An NTRU post-quantum solution was used to perform the key transport among the CPSs entities. We show that is feasible to integrate our post-quantum enhanced DTLS, together with the full Internet engineering task force protocol stack in highly constrained environments, such as the CPSs.
Shor’s algorithm efficiently solves factoring and discrete logarithm problems using quantum computers, compromising all public key schemes used today. Algorithms such as RSA, DHKE, and ECC will not work in a world with quantum computers, since they can easily invert the functions that provide their computational strength in the classical world. These schemes rely on assumptions on their computational complexity, which quantum computers can easily bypass. The solutions have to come from new algorithms – called Post-Quantum Cryptography (PQC) – or from new methods, such as Quantum Key Distribution (QKD). The former replicate the computational security ideas of classical public key algorithms, while the latter recurs to use the quantum properties of nature, which also brings a mathematical security proof, potentially offering Information-Theoretic Security. To secure data in the future, we must adopt these paradigms. With the speed of quantum computing advancements, the transition to quantum-safe cryptography within the next decade is critical. Delays could expose long-lived confidential data, as current encryption may be broken before its value expires. However, the shift must balance the adoption of new technologies with maintaining proven systems to protect against present and future threats. In this work, we have selected Transport Layer Security (TLS), one of the most widely used protocols, as the foundation to hybridize classical, quantum, and post-quantum cryptography in a way suitable for broad adoption in Software-Defined Networking (SDN), the most flexible networking paradigm that has been used to deploy integrated quantum–classical networks. To this end, we use standards for QKD key extraction and SDN integration. The purposed implementation is based on the latest version of TLS (1.3) and demonstrates advanced capabilities such as rekeying and key transport across a large QKD network, while supporting crypto-agility and maintaining backward compatibility through the use of ciphersuites. The performance of this approach has been demonstrated using a deployed production infrastructure.