BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//project/author//NONSGML v1.0//EN
CALSCALE:GREGORIAN
BEGIN:VEVENT
DTEND:20230106T120000Z
UID:05d47ae86961acad93e9522039098c48-390
DTSTAMP:19700101T120016Z
DESCRIPTION:The Right to Deny
URL;VALUE=URI:https://www.csa.iisc.ac.in/newweb/event/390/the-right-to-deny/
SUMMARY:Plausible deniability seems like the ultimate get-out-of-jail-free card. But how can we make it work when it comes to digital information sent in a public network. 

Deniable encryption, defined by Canetti et al (Crypto 1997), suggests a method to achieve deniability by the sender of encrypted messages to overcome this problem. The idea is especially interesting in the context of electronic elections to eliminate the threat of vote buying after a vote has been cast.

 
I will present two new works on the subject.

1) With Agarwal and S. Mossel (Crypto21) we define and construct sender Deniable Fully Homomorphic Encryption with compact ciphertexts based on the Learning With Errors (LWE) polynomial hardness assumption. Deniable FHE enables storing encrypted data in the cloud to be processed securely without decryption, maintaining deniability of the encrypted data.   

2) With Coladangelo and Vazirani (STOC22),  we show a sender deniable  encryption scheme where the encryption scheme is a quantum algorithm but the ciphertext is classical which is secure under the LWE polynomial hardness assumption. This scheme achieves for the first time simultaneously compactness, negligible deniability and polynomial encryption timeunder LWE. Furthermore, it is possible to extend the scheme so that coercion in an election cannot take place when the coercer is able to dictate all inputs to the deniable encryption algorithm even prior to encryption.
DTSTART:20230106T120000Z
END:VEVENT
END:VCALENDAR