The classical limitation of one-time-pad (OTP) cryptography is the key-distribution problem: to send n bits of plaintext, the parties must already share n bits of pre-distributed key. Once the pad is exhausted, the parties must meet again to exchange new pad material. This is widely viewed as making pure OTP impractical for sustained communication. We present a protocol that resolves this limitation: once an initial pad of size N is shared in person, subsequent pad material is generated by one party from a true-random source and transmitted as encrypted payload over the existing OTP channel itself. The receiver decrypts using existing pad and appends the recovered random bytes to its local pad. Net pad balance after a refill operation is unchanged — bytes of old pad are spent to deliver an equal number of bytes of new pad — but the new material is fresh, secret, and uncompromised. We prove inductively that information-theoretic security of the new pad is preserved across arbitrary refill chains. The result is a protocol with all the security guarantees of classical OTP and none of its practical key-distribution limitation, given a single in-person bootstrap.
The classical limitation of one-time-pad (OTP) cryptography is the key-distribution problem: to send n bits of plaintext, the parties must already share n bits of pre-distributed key. Once the pad is exhausted, the parties must meet again to exchange new pad material. This is widely viewed as making pure OTP impractical for sustained communication. We present a protocol that resolves this limitation: once an initial pad of size N is shared in person, subsequent pad material is generated by one party from a true-random source and transmitted as encrypted payload over the existing OTP channel itself. The receiver decrypts using existing pad and appends the recovered random bytes to its local pad. Net pad balance after a refill operation is unchanged — bytes of old pad are spent to deliver an equal number of bytes of new pad — but the new material is fresh, secret, and uncompromised. We prove inductively that information-theoretic security of the new pad is preserved across arbitrary refill chains. The result is a protocol with all the security guarantees of classical OTP and none of its practical key-distribution limitation, given a single in-person bootstrap.
Among the problems to guarantee secrecy for in-transit information, the difficulties involved in renewing cryptographic keys in a secure way using couriers, the perfect secrecy encryption method known as One-Time-Pad (OTP) became almost obsolete. Pure quantum key distribution (QKD) ideally offers security for key distribution and could revive OTP. However, special networks that may need optical fibers, satellite, relay stations, expensive detection equipment compared with telecom technology and the slow protocol offer powerful obstacles for widespread use of QKD. Classical encryption methods flood the secure communication landscape. Many of them rely its security on historical difficulties such as factoring of large numbers - their alleged security sometimes are presented as the difficulty to brake encryption by brute force. The possibility for a mathematical breakthrough that could make factoring trivial are poorly discussed. This work proposes a solution to bring perfect secrecy to in-transit communication and without the above problems. It shows the key distribution scheme (nicknamed KeyBITS Platform) based on classical signals carrying information but that carry with them recordings of quantum noise. Legitimate users start with a shared information of the coding bases used that gives them an information advantage that allows easy signal recovery. The recorded noise protects the legitimate users and block the attacker's access. This shared information is refreshed at the end of each batch of keys sent providing the secret shared information for the next round. With encryption keys distilled from securely transmitted signals at each round OTP can be revived and at fast speeds.
The One-Time-Pad (OTP) protocol gives unconditional security for the information being encrypted. Correctly implemented, not even an adversary with a quantum computer can crack it. However, the need of sharing in a secure way supplies of symmetric random keys turned the method almost obsolete as a stand-alone method for fast and large volume telecommunication. Basically, this secure sharing of keys and their renewal, once exhausted, had to be done through couriers, in a slow and costly process. This paper presents a solution for this problem providing a fast and unlimited renewal of secure keys: An untappable key distribution system is presented and detailed. This fast key distribution system utilizes two layers of confidentially protection: 1) Physical noise intrinsic to the optical channel that turn the coded signals into stealth signals and 2) Privacy amplification using a bit pool of refreshed entropy run after run, to eliminate any residual information. The resulting level of security is rigorously calculated and demonstrates that the level of information an eavesdropper could obtain is negligible. The random bit sequences, fast and securely distributed, can be used to encrypt text, data or voice.
One-time pad encrypted files can be sent through Internet channels using current Internet protocols. However, the need for renewing shared secret keys make this method unpractical. This work shows how users can use a fast physical random generator based on fluctuations of a light field and the Internet channel to directly boost key renewals. The transmitted signals are deterministic but carries imprinted noise that cannot be eliminated by the attacker. Thus, a one-time pad for Internet can be made practical. Security is achieved without third parties and not relying on the difficulty of factoring numbers in primes. An informational fragility to be avoided is discussed. Information-theoretic analysis is presented and bounds for secure operation are determined.
Using one-time pads is the only cryptographic solution that really ensures the secrecy of a transmitted message. The communicating parties have to meet in advance to establish the value of any one-time pad. This means that the two parties have to meet regularly to renew the batch of one-time pads they share. By contrast, we show that after developing a secret reading mask using any quantum key distribution algorithm, the two parties can communicate indefinitely by encrypting each of their messages with a one-time pad. The value of the one-time pad is quantum encrypted and transmitted prior to the transmission of the message itself.
In this thesis, a new practical method to realize one-time pad perfect secrecy for wireless \ncommunication is presented. Most commonly used security methods are based on cryp- tographic \ntechniques employed at the upper layers of a wireless network. These methods basically rely on the \ncomputational hardness of some mathematical problems. This com- putational complexity is vulnerable \nin nature due to fast-growing computational power of hardware technology, yet not taking into \naccount the revolution of Quantum computing in further future. Another core problematic issue \nexists in symmetric security systems; there is a deadlock between securing the channel and \nestablishing the shared key. We need the key for securing the channel, on the other hand, for \nsharing the key we need a secure channel. \n \nTo address such vulnerabilities, Physical Layer Security (PLS) has been widely studied in recent \nyears. PLS schemes build on the idea of turning unpredictable and random wire- less channel \ncharacteristics into a source for information-theoretic security. Information- theoretic security \nitself, relies on Shannon’s pioneer work . Shannon, inspired by one-time pad, also known as Vernam \ncipher, theoretically showed that the only unconditional per- fect secrecy system is a one-time pad \nwith a key at least as random as the plaintext, i.e., a system that uses a different random key to \ncipher any new plaintext. In PLS key genera- tion methods, legitimate parties alternately send \nprobe signals and estimate Channel State Information (CSI) of common random channel and then \nconvert enough amount of these estimates to secure shared keys. To achieve perfect secrecy, the key \ngeneration methods must meet the key randomness and Key Generation Rate (KGR) requirements of \ntheir specific cryptographic applications. \n \nIn this research a new practical system for achieving unconditional perfect secrecy is presented. \nOur system uses channel phase as the probing parameter to fully benefit from its uniform \ndistribution over [0, 2π]. It also uses an encryption method based on modulo- \n2π addition of phase values which is the perfect counterpart of XOR addition in binary one-time \npad. Moreover, by intentionally perturbing the wireless channel in vicinity of the transceiver \nantenna based on RF-mirrors structure, it produces different random phase values in each channel \nprobing, much faster than the inherent channel variation would do, resulting in dramatically higher \nKGR than any wide-band PLS scheme presented so far and realizing true perfect secrecy. Most \nimportantly, the focus of this research is a detailed practical algorithm for implementing the \nsystem as well as empirical results which makes \nour system the first channel-phase-based PLS scheme implementation, reported so far.
Although it is widely deemed impossible to overcome the information theoretic optimality of the one-time pad (OTP) cipher in pre-and post-quantum cryptography, this work shows that the optimality of information theoretic security (ITS) of OTP is paradoxical from the perspective of information conservational computing and cryptography. To prove this point, ITS of OTP is extended to information conservational security (ICS) of scalable OTP (S-OTP) with percentage-based key extension where total key length can be reduced to a condensed tiny minimum through “black hole” keypad compression coupled with “big bang” data recov-ery. The cost is a limited 25%+ increase in total data length and network traffic; the gain is to makes the transmission of long messages possible without weakening ITS/OTP. It is proven that if ITS/OTP were optimal, ICS/S-OTP would be impossible; on the other hand, if ICS/S-OTP were not information theoretically secure, ITS/OTP would not be secure either. Thus, we have a proof by contradiction on the paradoxical nature of OTP optimality. It is further proven that a summation with percentage distribution is a special case of equilibrium-based bipolar quantum cellular automata. This proof bridges a classical world with a quantum world and makes it possible to combine the advantages of both approaches for pre-and post-quantum cryptography. It is suggested that the findings of this work form an analytical paradigm of quantum intelligence machinery toward perfect information conservational security. Some mysteries in nature and science are identified. In particular, the question is posted: Could modern science have been like a well-founded building with a floor of observable beings and truths but missing its roof for equilibrium, harmony, information conservation, and logically definable causality?.