McAfee’s statement, “We live in a system of permission,” encapsulates the current reality:

Privacy is not ours by default, it’s granted or revoked by external powers.

In finance, cryptocurrencies helped us opt out of the system, giving individuals autonomy over their money.

For privacy, we must do the same by rejecting regulations that weaken encryption or enforce surveillance.

To uphold the same standards for privacy as we do for cryptocurrencies, we must build more permissionless, trustless, and decentralized networks that are attac{less}.

Through the lens of surveillance, we unveil the unseen patterns of control.

Every trace, every line reveals a story of watching and being watched.

Are you the observer, or the observed?

Privacy is not a game

Privacy is a Fundamental Human Right

Philosophically, privacy is tied to autonomy and self-ownership, core libertarian values. In economics, data can be viewed as personal property, deserving protection akin to physical assets. Privacy is an inalienable right, not a negotiable privilege subject to permission.

Protecting metadata in communication is critical to achieving complete privacy.

Officials at the NSA have stated that:

“if you have enough metadata you don’t really need content” and that “we kill people based on metadata”.

Unbeknownst, there’s a plethora of threat models that most users aren’t even aware off.

Threats that wrap their tentacles on your device and suck out all of your metadata, rendering the the most common e2ee or p2p solutions useless against attackers for the average user.

The intense pressure in the past years to deliver solutions quickly has resulted in varying threat models, incomplete objectives, dubious security claims, and a lack of broad perspective on the adaptation scale of secure communications.

Unfortunately, state-of-the-art private messaging systems are unable to protect metadata for large numbers of users.

Existing work falls into two broad categories.

On one hand are systems that provide strong, provable privacy guarantees, that although they can protect metadata, they either rely on broadcasting all messages to all users, or use computationally expensive cryptographic constructions to trade off computation for bandwidth.
As a result, these systems have scaled to just thousands users or hundreds of messages per second.
On the other hand, scalable systems like Tor and mixnets provide little protection against powerful adversaries that can observe and tamper with network traffic.
These systems require a large number of users to provide any degree of privacy, so as to increase the anonymity set for each user, but even then are susceptible to traffic analysis.

Introducing PingPong 🏓

a protocol of attac{less} ping-to-ping private communications.

PingPong is a client-server network, nodes asynchronously pass messages via unidirectional message queues providing hardened network layer recipient and sender anonymity.

Ping {the app} is server-less, stores no metadata, requires no ID or phone number and all the messages are encrypted and ephemerally routed. Ping makes it impossible to be censored. There is no middleman involved.

All the messages are directly sent ping-to-ping.

Ping prevents an adversary from learning which pairs of users are communicating, as long as just one out of relays is not compromised, even for users who continue to use Ping for years.

Ping uses only simple, fast cryptographic primitives, and, using community nodes, can scale to millions of users and tens of thousands of messages per second. At the same time, Ping can provide guarantees at a small scale, without the need for a large anonymity set: even if just two users are using the system, an adversary will not be able to tell whether the two users are talking to each other.

Core Protocol Features

Quantum resistant e2e encryption

End-to-end encryption in each message queue using NaCI cryptobox. This is added to allow redundancy in the future (passing each message via several servers), to avoid having the same ciphertext in different queues (that would only be visible to the attacker if TLS is compromised).

Complete privacy of your identity, profile, contacts and metadata

Ping has no identifiers assigned to the users not even random numbers. This protects the privacy of who are you communicating with, hiding it from Ping platform servers and from any observers.

Embedded EXIF Removal

Exif is data about data, this additional information attached to files can lead us to share significantly more information than we intended to. For example, if you send an image, but don't remove the metadata, it may reveal the location (GPS lat + long) of where it was taken, the device is was taken on, precise camera data, details about modifications and the picture source + author. This could obviously pose a security risk. Delet! users exif data from a media/file before sharing content in the chat.

Full ownership, control and security of your data

Ping stores all user data on client devices, the messages are only held temporarily on PingPong relay nodes until they are received.

Mitigation of Time Analysis

Message mixing adds latency to message delivery, to protect against traffic correlation by message time.

Protec against spam and abuse

As you have no identifier on Ping, you cannot be contacted unless you share a one-time invitation link or an optional temporary user address.

Traffic analysis resistant noise

Our design assumes an adversary who controls all but one of the PingPong nodes (users need not know which one), controls an arbitrary number of clients, and can monitor, block, delay, or inject traffic on any network link. As adversaries can still learn a lot by performing traffic analysis, noise prevents them doing so.

Encrypted database recovery

Local database encryption, your contacts, groups and all sent and received messages are stored encrypted. Oblivious Pseudorandom Functions (OPRFs) and a Secret-Sharing Scheme (SSS) distributed storage recovery of secrets. Short pin instead of long strings of encryption keys.

We have defined core privacy properties:

Sender Anonymity: When a chat message is received, no non-global entities except for the sender can determine which entity produced the message.
Recipient Anonymity: No non-global entities except the receiver of a chat message know which entity received it.
Participation Anonymity: No non-global entities except the conversation participants can discover which set of network nodes are engaged in a conversation.
Unlinkability: No non-global entities except the conversation participants can discover that two protocol messages belong to the same conversation.
Global Adversary Resistant: Global adversaries cannot break the anonymity of the protocol.

When evaluating the security and privacy properties in secure messaging, we must consider a variety of adversaries. Our threat model includes the following attackers:

Local Adversary (active/passive): An attacker controlling local networks (e.g., owners of open wireless access points).
Global Adversary (active/passive): An attacker controlling large segments of the Internet, such as powerful nation states or large internet service providers.
Service providers: For messaging systems that require centralized infrastructure (e.g., public-key directories), the service operators should be considered as potential adversaries.

Note that our adversary classes are not necessarily exclusive. In some cases, adversaries of different types might collude.

We also assume that all adversaries are participants in the messaging system, allowing them to start conversations, send messages, or perform other normal participant actions.

We assume that the endpoints in a secure messaging system are secure (i.e., malware and hardware attacks are out of scope)

Our protocol design allows us to assume that Ping is not vulnerable to neither of the listed adversaries threat models, unless the devices are physically compromised.

PoP consensus {Proof of Ping}

All P2P networks are likely to be vulnerable to Sybil attacks, because each node is discoverable, and the network operates as a whole. Measures to reduce the probability of the Sybil attack either require a centralized component or expensive proof-of-work.

The proposed design, on the opposite, has no central authority, no server discoverability, nodes are not connected, unknown to each other and to all clients.

Unlike P2P networks, all messages are passed through one or several server nodes, that do not even need to have persistence. Using in-memory message storage, persisting only the queue records. Ping provides better metadata protection than P2P designs, as no global participant identifiers are used to deliver messages, and avoids the problems of p2p networks.

Unlike federated networks, the server nodes do not have records of the users, do not communicate with each otherand do not store messages after they are delivered to the recipients. There is no way to discover the full list of nodes participating in the PingPong network.

This design avoids the problem of metadata visibility that all federated networks have and better protects from the network-wide attacks.

PoP will guarantee ping-to-ping messaging between users in a way that is private in the face of a strong adversary, who can observe and tamper with the entire network traffic and all but one of PingPong’s relay nodes.

That is, an adversary should not be able to distinguish between a scenario where two particular users are communicating, and a scenario where they are not, even after interfering with the system.

A constellation of nodes scattered globally securing and scaling the network.

hardware requirements/incentives tba*

Out of the secure communications sandbox, what good is private communication without private networks or private money.

We can’t securely use one or the other without all of the privacy tools working in sync.

That is why we are fully committed to explore the endless opportunities that have presented themselves with the advent development of Privacy 2.0.

Ping, pong, no one sees, no one knows…

Legal Indifference
PingPong should be unconcerned with the laws of nation states, just like other internet protocols. Regulators will have to figure out how to respond to the functionality enabled by Privacy 2.0 powered technology, not the other way around.

ATTAC{less} / a privacy Manifesto