End-to-end encryption

End-to-end encryption (E2EE) is a private communication system in which only communicating users can participate. As such, no one, including the communication system provider, telecom providers, Internet providers or malicious actors, can access the cryptographic keys needed to converse. End-to-end encryption is intended to prevent data being read or secretly modified, other than by the true sender and recipient(s). The messages are encrypted by the sender but the third party does not have a means to decrypt them, and stores them encrypted. The recipients retrieve the encrypted data and decrypt it themselves. Because no third parties can decipher the data being communicated or stored, for example, companies that provide end-to-end encryption are unable to hand over texts of their customers' messages to the authorities. In 2022, the UK's Information Commissioner's Office, the government body responsible for enforcing online data standards, stated that opposition to E2EE was misinformed and the debate too unbalanced, with too little focus on benefits, since E2EE "helped keep children safe online" and law enforcement access to stored data on servers was "not the only way" to find abusers. In many messaging systems, including email and many chat networks, messages pass through intermediaries and are stored by a third party, from which they are retrieved by the recipient. Even if the messages are encrypted, they are only encrypted 'in transit', and are thus accessible by the service provider, regardless of whether server-side disk encryption is used. Server-side disk encryption simply prevents unauthorized users from viewing this information. It does not prevent the company itself from viewing the information, as they have the key and can simply decrypt this data. This allows the third party to provide search and other features, or to scan for illegal and unacceptable content, but also means they can be read and misused by anyone who has access to the stored messages on the third-party system, whether this is by design or via a backdoor.

Scalable and Privacy-Preserving Federated Principal Component Analysis

Jean-Pierre Hubaux, Juan Ramón Troncoso-Pastoriza, Jean-Philippe Léonard Bossuat, Apostolos Pyrgelis, David Jules Froelicher, Joao André Gomes de Sá e Sousa

Principal component analysis (PCA) is an essential algorithm for dimensionality reduction in many data science domains. We address the problem of performing a federated PCA on private data distributed among multiple data providers while ensuring data confi ...

IEEE COMPUTER SOC2023

On the Theory and Practice of Modern Secure Messaging

Scalable and Privacy-Preserving Federated Principal Component Analysis

Thwarting Malicious Adversaries in Homomorphic Encryption Pipelines

On the Theory and Practice of Modern Secure Messaging

Scalable and Privacy-Preserving Federated Principal Component Analysis

Thwarting Malicious Adversaries in Homomorphic Encryption Pipelines