Subject:
Computer Science And Mathematics,
Mathematics
Keywords:
Proxy re-encryption; re-encryption simulatability; honest re-encryption attacks; learning with errors; quantum-resistant
Online: 28 November 2023 (10:22:47 CET)
Proxy re-encryption (PRE) is a momentous and widely used cryptographic technique. It enables a proxy to forward ciphertext without the need of decryption. PRE has received significant interest in applications like cloud computing, blockchain, and the Internet of Things. Despite its wide range of uses, PRE has also been subject to new security and privacy regulations. In PKC’19, Cohen $et~al.$~first drew attention to the weakness in PRE's security against chosen-plaintext attacks (CPA) and put up a more stringent security concept known as security against honest re-encryption attacks (HRA). Notably, Cohen provides a beneficial conclusion as well. It is proveded that PRE schemes with re-encryption simulatability property can be elevated from CPA to HRA security. It is also proved that CPA-secure PRE schemes with re-encryption simulatability property can be directly elevated to those satisfying HRA security. However, those PRE schemes with re-encryption simulatability are almost always based on pairings. In this study, to the best of our knowledge, we directly construct HRA-secure PRE with re-encryption simulatability for the first time based on the learning with errors (LWE) assumption, which was widely believed to be quantum-resistant. Based on the re-encryption key generation algorithm and the re-encryption algorithm construction method of the above scheme, we can modify attribute-based conditional proxy re-encryption (AB-CPRE) as well as the corresponding attribute-based proxy re-encryption (AB-PRE) algorithm to make them have re-encryption simulatability properties. Finally, by using this property, We boost the security of AB-CPRE scheme of ESORICS'21 from CPA to HRA and simplify the HRA-security proof for the AB-PRE of ESORICS'21.
Subject:
Biology And Life Sciences,
Other
Keywords:
depression; nurturing; honest signaling; reproductive suppression; anthocyanins; hormesis
Online: 15 July 2019 (13:31:03 CEST)
Background: Solon (2019) introduced genetic bandwagoning in a very general sense: A variant sequentially 1) evaluates its holder’s quality and 2) induces its holder to relinquish resources if the holder’s quality is low. Here, I introduce a more complex form of bandwagoning in order to account for a series of phenomena considered “paradoxical” by scientists specializing in their literatures: a) depression, b) differential nurturing, c) honest signaling of quality, d) reproductive suppression, e) stress-induced anthocyanins, and f) hormesis. These literatures are characterized by the following findings: 1) Low-quality individuals incur a cost against reproductive success compared to higher-quality individuals. 2) Individuals not (yet) identified as low-quality incur a cost against their ability to survive predators and/or parasites compared to individuals that have already been identified as low-quality. 3) Females incur a cost against reproductive success compared to males. 4) Males incur a cost against their ability to survive predators and/or parasites compared to females. 5) If conditions are challenging, individuals gain in both reproductive success and their ability to survive predators and/or parasites compared to less challenging conditions; however, too-challenging conditions detract from both. For each literature, at least one of these findings is unaccommodated by existing theory when considered in the context of that literature. Despite existing theory, these patterns are remarkably persistent. Question: Can paradoxes fitting these patterns be explained by genetic bandwagoning theory? Conclusion: Here, reservation is introduced as a form of bandwagoning in which a bandwagoning variant induces its holder to reserve from (i.e., withhold) some of its ability to survive parasites or predators. Reservation would occur for the purpose of assessing a holder’s quality when conditions are sufficiently unchallenging that few individuals are chronically stressed, so it is otherwise difficult to evaluate a holder’s quality. If the holder is subsequently killed, wounded, or infected, then it is identified as lacking the quality that would allow its descendants to survive more challenging conditions. The holder loses some or all of its resources as a direct consequence of the very death, wounding, or infection that identified its low quality. That is, in reservation, the two steps of bandwagoning are accomplished simultaneously. (This way of bandwagoning is distinguished from when the two steps are accomplished sequentially, which is termed resonation.) Reservation shares numerous premises with Zahavi’s handicap principle. If conditions are challenging, individuals would downregulate reservation and also be less likely to forego resources through resonation (which accounts for (5)). Additionally, a bandwagoning variant would likely evolve to vary the reservation it induces from holder to holder as a hedge against the possibility that conditions suddenly turn severe before it can adjust the reservation. Individuals already identified as low-quality would downregulate reservation (which accounts for (2) above) and would instead forego resources through resonation (which accounts for (1)). Additionally, females would downregulate reservation (which accounts for (4)) and, as a consequence, surviving females are more likely than surviving males to forego resources through resonation (which accounts for (3)).