Riffle is an anonymity network developed by researchers at

MIT The Massachusetts Institute of Technology (MIT) is a private research university in Cambridge, Massachusetts, United States. Established in 1861, MIT has played a significant role in the development of many areas of modern technology and sc ...

and EPFL as a response to the problems of the Tor network. Riffle employs a

privacy Privacy (, ) is the ability of an individual or group to seclude themselves or information about themselves, and thereby express themselves selectively. The domain of privacy partially overlaps with security, which can include the concepts of a ...

-enhancing protocol that provides strong

anonymity Anonymity describes situations where the acting person's identity is unknown. Anonymity may be created unintentionally through the loss of identifying information due to the passage of time or a destructive event, or intentionally if a person cho ...

for secure and anonymous communication within groups. The protocol is designed using the anytrust model, which ensures that even if colluding servers attempt to compromise the privacy of the group, they cannot do so if at least one server in the group is honest. Like Tor, it utilizes

onion routing Onion routing is a technique for anonymous communication over a computer network. In an onion network, messages are encapsulated in layers of encryption, analogous to the layers of an onion. The encrypted data is transmitted through a series o ...

. According to MIT's Larry Hardesty, researchers at MIT and the Qatar Computing Research Institute demonstrated a vulnerability in Tor's design. To achieve its goals, Riffle implements two distinct protocols: the Hybrid Shuffle protocol for sending and

Private Information Retrieval In cryptography, a private information retrieval (PIR) protocol is a protocol that allows a user to retrieve an item from a server in possession of a database without revealing which item is retrieved. PIR is a weaker version of 1-out-of-''n'' obl ...

(PIR) for receiving. For sending information, Riffle uses a hybrid shuffle, consisted of a verifiable shuffle and a

symmetric-key algorithm Symmetric-key algorithms are algorithms for cryptography that use the same cryptographic keys for both the encryption of plaintext and the decryption of ciphertext. The keys may be identical, or there may be a simple transformation to go between ...

. The Hybrid Shuffle protocol consists of a setup phase and a transmission phase. During the setup phase, a slow verifiable shuffle based on

public key cryptography Public-key cryptography, or asymmetric cryptography, is the field of cryptographic systems that use pairs of related keys. Each key pair consists of a public key and a corresponding private key. Key pairs are generated with cryptographic al ...

is used, while an efficient shuffle based on symmetric key cryptography is used during the transmission phase. Messages sent over Riffle are not forwarded if they have been altered by a compromised server. The server has to attach

proof Proof most often refers to: * Proof (truth), argument or sufficient evidence for the truth of a proposition * Alcohol proof, a measure of an alcoholic drink's strength Proof may also refer to: Mathematics and formal logic * Formal proof, a co ...

in order to forward the message. If a server encounters unauthenticated messages or different permutations, it exposes the signed message of the previous server and runs the accusation protocol to ensure

verifiability Verification or verify may refer to: General * Verification and validation, in engineering or quality management systems, is the act of reviewing, inspecting or testing, in order to establish and document that a product, service or system meets ...

without requiring computationally intensive protocols during transmission phases. For receiving information it utilizes multi-server

. All servers in the system share a replicated database, and when a client requests an entry from the

database In computing, a database is an organized collection of data or a type of data store based on the use of a database management system (DBMS), the software that interacts with end users, applications, and the database itself to capture and a ...

, they can cooperatively access it without knowing which entry they are accessing. The main intended use-case is anonymous

file sharing File sharing is the practice of distributing or providing access to digital media, such as computer programs, multimedia (audio, images and video), documents or electronic books. Common methods of storage, transmission and dispersion include ...

. According to the lead project researcher, Riffle is intended to be complementary to Tor, not a replacement.

References

External links

Riffle code at GitHub
Anonymity networks Massachusetts Institute of Technology {{Internet-stub

See also

References

External links