Auflistung nach Schlagwort "unlinkability"
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- KonferenzbeitragA Non-Sequential Unsplittable Privacy-Protecting Multi-Coupon Scheme(Informatik 2007 – Informatik trifft Logistik – Band 2, 2007) Escalante B., Alberto N.; Löhr, Hans; Sadeghi, Ahmad-RezaA multi-coupon (MC ) represents a collection of k coupons that a user can redeem to a vendor in exchange for a benefit (some good or service). Recently, Chen et al. [CEL+07] proposed an unforgeable privacy-protecting multi-coupon scheme (MCS), which discourages sharing of coupons through a property called unsplitta- bility, where the coupons of a single MC cannot be separately used by two users. Pre- vious MCSs relied on the all-or-nothing principle, a weaker form of unsplittability, where sharing a single coupon implies sharing the whole multi-coupon. The construc- tion proposed in [CEL+07] supports coupons with practical attributes: independent benefits, and validity periods (e.g., expiration dates). However, it has the disadvantage that the coupons contained in an MC must be redeemed in sequential order. Hence, it is suitable for fewer applications. In this paper, we address this problem and propose a scheme that satisfies the same set of security requirements, supports the same practical attributes, and offers similar efficiency, but in which users are able to choose which coupon they redeem.
- KonferenzbeitragTemplate Protection: On the need to adapt the current Unlinkability Evaluation Protocol(BIOSIG 2022, 2022) Simon Kirchgasser and Andreas UhlUsing ISO/IEC Standards an evaluation protocol exists which properties need to be fulfilled by each template protection scheme. However, in these standards it is not defined how a sensible and sensitive key selection should be done such that the demanded properties are reached. For the analysis regarding the ISO/IEC Standards properties only arbitrary, randomly selected keys are usually used, but it is not considered that in this case the key selection might result in insufficiently protected biometric images (templates). By the performed experiments using not only randomly selected keys, but also considering the best of insufficient (improper) keys, it was revealed that the unlinkability evaluation protocol is influenced by the key selection. Hence, it is recommended to use both mentioned key types to analyse template protection methods. This means that the protocol has to be fine-tuned, in so far that for the best of the worst key choice (which then has to be used in the protocol) unlinkability still needs to be given.