Grant: CCI Applied Research and Development Grants

It is becoming more and more common to exchange sensitive documents electronically, remoted work as definitely accelerated the trend that was already rising. Throughout the exchange, it is essential to protect the confidentiality of the document. When this is done in a client-to-server context, the problem is relatively easy since the server can deploy a cryptographic infrastructure on which the client can rely (e.g., using asymmetric cryptography to solve the key exchange problem). However, the problem becomes much more complex in a client-to-client context where neither party as the means and know-how to deploy the necessary underlying cryptographic infrastructure. The key exchange problem is particularly problematic in a client-to-client situation. As a result, solutions are often ad hoc, insecure, or worst documents are sent unencrypted. This project will study an approach to achieve end-to-end encryption in a client-to-client communication context. End-to-end encryption means that the document cannot be decrypted by any intermediate party (e.g., a mail server) in the exchange process; only the initial sender and final receiver are allowed to access the content. Moreover, the project will tackle the related problem of achieving source authentication (i.e., digital signature) of a sensitive document. To maintain the confidentiality of the document, it cannot be sent to a third party for signature. However, if the signature is performed locally by the sender, it becomes very difficult for the receiver to validate/trust the signature.