A transaction-spreading method that first relays along a narrow stem path and then broadcasts in a wider fluff phase. Monero uses it to make the original network source harder to infer.
Also called: Dandelion, stem, fluff.
Stem first, wider broadcast later
Dandelion++ separates transaction propagation into two phases. In the stem phase, a transaction follows a narrow forwarding path. In the fluff phase, it spreads more widely across peers.
This makes the node first observed broadcasting widely a less direct indicator of the original source. Monero's relay implementation manages stem routes, fluff behavior and fallback handling so transactions can still reach the network.
References: Dandelion++ research paper · Monero source: cryptonote_protocol/levin_notify.cpp
Observing a relayed payment
Imagine a peer sees a transaction arriving from another node. That sender might have created it or might be forwarding it. Wider broadcast alone does not establish which wallet originally submitted the payment.
That uncertainty depends on the observer's position and the connections involved. A node receiving a wallet's RPC submission can know that the wallet connection delivered the transaction before later peer-to-peer relay occurs.
References: Monero source: cryptonote_protocol/levin_notify.cpp · Remote node documentation
Dandelion++ alongside Tor and I2P
Dandelion++ changes the way nodes spread transactions. It does not create a Tor circuit, encrypt every network connection or conceal an IP address from a directly connected peer.
Monero supports separate Tor and I2P routing options. Which traffic uses those routes depends on configuration. The presence of Dandelion++ does not prove that wallet-to-node requests or all daemon traffic use an anonymity network.
References: Monero source: cryptonote_protocol/levin_notify.cpp · Daemon options and console commands
Network assumptions and observer access
The research paper analyzes anonymity under explicit network and adversary assumptions. The analysis does not promise anonymity against every possible observer.
A local node, an inbound peer and a remote wallet service can expose different observations. For practical configuration, examine the actual wallet connection and relay path as well as the cryptographic transaction format.
References: Dandelion++ research paper · Remote node documentation
Related glossary terms
Practical guides
Technical baseline: v0.18.5.4. Reviewed 2026-11-08 UTC.