Trusted third party | EPFL Graph Search

In cryptography, a trusted third party (TTP) is an entity which facilitates interactions between two parties who both trust the third party; the third party reviews all critical transaction communications between the parties, based on the ease of creating fraudulent digital content. In TTP models, the relying parties use this trust to secure their own interactions. TTPs are common in any number of commercial transactions and in cryptographic digital transactions as well as cryptographic protocols, for example, a certificate authority (CA) would issue a digital certificate to one of the two parties in the next example. The CA then becomes the TTP to that certificate's issuance. Likewise transactions that need a third party recordation would also need a third-party repository service of some kind. 'Trusted' means that a system needs to be trusted to act in your interests, but it has the option (either at will or involuntarily) to act against your interests. 'Trusted' also means that there is no way to verify if that system is operating in your interests, hence the need to trust it. Corollary: if a system can be verified to operate in your interests, it would not need your trust. And if it can be shown to operate against your interests one would not use it. Suppose Alice and Bob wish to communicate securely – they may choose to use cryptography. Without ever having met Bob, Alice may need to obtain a key to use to encrypt messages to him. In this case, a TTP is a third party who may have previously seen Bob (in person), or is otherwise willing to vouch for that this key (typically in a public key certificate) belongs to the person indicated in that certificate, in this case, Bob. Let's call this third person Trent. Trent gives Bob's key to Alice, who then uses it to send secure messages to Bob. Alice can trust this key to be Bob's if she trusts Trent. In such discussions, it is simply assumed that she has valid reasons to do so (of course there is the issue of Alice and Bob being able to properly identify Trent as Trent and not someone impersonating Trent).

Attestable Software Versioning for Stateful Confidential Computing

Edouard Bugnion, Charly Nicolas Lucien Castes

Trusted execution environments enable the creation of confidential and attestable enclaves that exclude the platform and service providers from the trusted base. From its initial attestable state, a stateful enclave such as a confidential database can hold ...

2022

Secured Routines: Language-based Construction of Trusted Execution Environments

James Richard Larus, Edouard Bugnion, Adrien Ghosn

Trusted Execution Environments (TEEs), such as Intel SGX enclaves, use hardware to ensure the confidentiality and integrity of operations on sensitive data. While the technology is available on many processors, the complexity of its programming model and i ...

USENIX ASSOC2019

Poster: LocalCoin: An Ad-hoc Payment Scheme for Areas with High Connectivity

Boi Faltings, Sujit Prakash Gujar, Dimitrios Chatzopoulos

The popularity of digital currencies, especially cryptocurrencies, has been continuously growing since the appearance of Bitcoin. Bitcoin is a peer-to-peer (P2P) cryptocurrency protocol enabling transactions between individuals without the need of a truste ...

Assoc Computing Machinery2016