ZeroHour

Search: “broadcast encryption”

2 stories in the last 30d

Large Universe Subset Predicate Encryption with IND-CCA Security (with Constant-size Ciphertext and Keys)

New construction achieves first large-universe subset predicate encryption with IND-CCA security and constant-size ciphertexts and keys under subgroup decision assumptions.

The paper proposes the first large-universe subset predicate encryption scheme achieving IND-CCA security with both constant-size ciphertexts and constant-size secret keys. Prior large-universe constructions by Chatterjee and Mukherjee either achieved only restricted selective security with constant sizes or adaptive security with attribute-dependent ciphertext size, and none achieved CCA security. The new construction is proven selectively secure under standard subgroup decision problems. Black-box transformations yield the first CCA-secure WIBE and WKD-IBE with constant-size ciphertexts and keys.

arXiv cs.CR · 2d agoResearch

Risky Bulletin: Expired cards can be used for new transactions

Researchers show expired Visa contactless cards can be revived via NFC man-in-the-middle relay to run fraudulent transactions; roundup also covers major breaches.

University of Massachusetts Amherst researchers built an NFC man-in-the-middle rig that updates a card's expiration date in transit and relays the modified payment to POS terminals, reviving expired contactless cards; Visa terminals and the backends of all five banks studied failed to catch the manipulation. The same roundup reports Iranian hackers shut down a small UK power plant for four days, Lazarus breached South Korea's Presidential Office as part of a campaign exceeding 100 victims, and French telecom SFR suffered a breach affecting over 2.1 million customers.

Risky Business News · 24d agoResearch1