We provide an extensive cryptographic analysis of Threema, a Swiss-based encrypted
messaging application with more than 10 million users and 7000 corporate customers. We …

AWS Lambda is a serverless event-driven compute service, part of a category of cloud
compute offerings sometimes called Function-as-a-service (FaaS). When we first released …

MEGA is a leading cloud storage platform with more than 250 million users and 1000
Petabytes of stored data. MEGA claims to offer user-controlled, end-to-end security. This is …

Popular messaging applications now enable end-to-end-encryption (E2EE) by default, and
E2EE data storage is becoming common. These important advances for security and privacy …

Web users can gather data from secure endpoints and demonstrate the provenance of
sensitive data to any third party by using privacy-preserving TLS oracles. In practice, privacy …

Abstract Key Encapsulation Mechanisms (KEMs) are a critical building block for hybrid
encryption and modern security protocols, notably in the post-quantum setting. Given the …

The Duplex construction, introduced by Bertoni et al.(SAC 2011), is the Swiss Army knife of
permutation-based cryptography. It can be used to realise a variety of cryptographic objects …

As end-to-end encrypted messaging services become widely adopted, law enforcement
agencies have increasingly expressed concern that such services interfere with their ability …

Context-committing security of authenticated encryption (AE) that prevents ciphertexts from
being decrypted with distinct decryption contexts,(K, N, A) comprising a key K, a nonce N …

A line of recent work has highlighted the importance of context commitment security, which
asks that authenticated encryption with associated data (AEAD) schemes will not decrypt the …