Physalia: Redistribution-Resistant Content Protection for Decentralized Storage
[Kryptografia i bezpieczeństwo] Autorzy: Giacomo Giuliari, Karl Wüst
In decentralized storage systems, access control is often implemented by encrypting the data before upload and sharing the decryption key with authorized parties. A leaked key, however, makes the data publicly accessible, which lowers the barrier to content piracy below that of traditional systems, where piracy requires redistributing the full data. We present Physalia, an end-to-end access-control system for decentralized storage that secret-shares the data itself, instead of just the key, across multiple servers. Leaking the data then requires transmitting it in full: We formalize this intuition and introduce the redistribution bandwidth an adversary must pay to leak protected content and show that Physalia raises it to the size of the data. Sharing across untrusted servers requires robustness against corrupted shares. We develop a robustness transform that turns any computational sec…
- Kategoria arxiv
- cs.CR
- Kategoria
- Kryptografia i bezpieczeństwo