Different optical encryption schemes for secure PON and VPN systems are discussed and their confidentiality evaluated, within an accurate cryptanalysis framework. We consider both optical bit- and block-ciphering, and quantum-noise data protection.
We present different optical secure point-to-point transmission schemes using a planar multiport encoder/decoder. We consider both bit- and block-cipher cryptography: in the first case, each bit (both mark and space) from each user is encoded in a two-key optical code-division multiplexing signal. Block-cipher cryptography encodes a stream ofnbits into a single code and corresponds to opticalM-ary transmission. We demonstrate that block-ciphers are more secure with respect to bit-ciphers schemes and also against known-plaintext and chosen-plaintext attacks.
The Internet plays an essential role in modern societies and in the amount of sensitive data transported over the optical networks that shows its' importance has increased drastically. Therefore, it is critical to develop data protection schemes for optical fiber communications to provide user security. The Y-00 quantum-noise randomized stream cipher that employs extremely high-order modulation and restricts an attacker's interception of ciphertext is a practical candidate for providing data protection. In this article, we introduce the operation principle of the Y-00 cipher with respect to data encryption and decryption. The Y-00 cipher combines the mathematical encryption of multi-level signaling and physical randomness, and provides a high level of security to the physical layer of optical communications and a high communication performance. We also present the noise masking phenomenon of the Y-00 cipher with intensity modulation (IM). This noise masking is generated by shot noise, i.e., quantum noise and additive noise such as amplified spontaneous emission noise. The noise masking phenomenon fails an attacker's interception of the ciphertext. The secrecy of the IM Y-00 cipher is also discussed, and an approximate analytical solution is introduced for evaluating the probability of the attackers accurately guessing the ciphertext. Finally, the secrecy of a 1,000-km transmission system is experimentally demonstrated with the Y-00 cipher transceiver at data rate of 1.5-Gb/s using the derived analytical solution to deduce the high secrecy of the entire transmission system.
3GPP is currently considering the introduction of the 256-bit variant of symmetric-key cryptographic algorithms for beyond 5G Advanced systems, in addition to the 128-bit algorithms to attain higher security strength. In the recent years, a new security scheme called, Authenticated Encryption with Associated Data (AEAD) has been gaining popularity, and claims to be fast enough to provide confidentiality and integrity protection together with reduced instruction cycles. It is of interest, to consider such efficient algorithms for user plane protection in 5G and beyond, to maintain stringent performance metrics without compromising on security in a post quantum era. In this paper, we provide state-of-the-art performance evaluation on a test bed and propose the usage of AEAD scheme implemented using AES-GCM (AES-Galois Counter Mode) operation in 5G Systems for achieving higher security strength of quantum-resistant communications. We further extended our exploration to assess the performance impact of integrating AEAD with the quantum resistant variants of protocols PQ-TLS, IKEv2 with PPKs for an end-to-end user plane security. We performed a comparative analysis of the 256-bit variant of AES-GCM mode of operation with traditional AES modes of operation in 128-bit and 256-bit variants, by considering performance metrics such as throughput, energy consumption, CPU utilization and latency. We have observed that, AES-256 GCM provides an increase in throughput by 9.4% when both ciphering and integrity protection are applied. Similarly, we observed a reduction of 200% in latency for AES-256 GCM than that of AES-128 modes of operations. We also ran experiments on energy utilization and CPU utilization and observed that AES-256 GCM consumes 16% more energy and CPU cycles utilization is more than AES-256 CTR. From the evaluation results, we observed that the transition to 256-bit crypto algorithms is needed not only for realizing a quantum secure system, but also to increase the system performance.