Monero (XMR) Developers Draft FCMP++ Timeline for Proofs Across 150 Million Outputs

FCMP++ Replaces 16-Member Rings

Monero (XMR) price slipped 5.6% across the past 24 hours, but the privacy-focused altcoin's bigger development sits in its codebase. Developers are preparing FCMP++, an upgrade that would retire the ring signatures concealing every Monero (XMR) spend; it is not live yet, and no official fork date exists. The acronym covers Full-Chain Membership Proofs plus spend authorisation and linkability. A transaction under today's rules hides its true input inside a ring of 16 candidates; under FCMP++ it would prove that the input spends one of every spendable output on the chain, a set the developers size at more than 150 million. The current stack uses three tools, one per payment leg. Ring signatures cover the sender: since the network upgrade of August 2022, every ring holds 16 members, so each input points to 16 possible sources with only one real. Stealth addresses cover the receiver, because the sender's wallet mints a one-time address per payment, and two transfers to the same published address look unrelated to outsiders. Ring Confidential Transactions cover the amount; they went live in January 2017 and became mandatory in September 2017. A block explorer shows only the 16 ring members, one-time output addresses and unknown amounts. Academic research stress-tested that design and found early cracks. A 2017 study led by Kumar pinpointed the genuine spend in 87% of the cases reviewed, and a 2018 paper by Möser and colleagues showed many early inputs carried no decoys at all, letting researchers eliminate spent coins from other rings. Protocol changes closed most of those holes: a minimum ring size ended decoy-free spends, RingCT inputs proved largely immune to the chain-reaction analysis the 2018 paper described, and wallets now select decoys along the spending-time curve that very paper measured. One weak point survives at the user level: repeated payments with the same counterparty hand that party a statistical angle if it decides to follow the funds.

Draft Timeline Stretches to March 2027

The only public schedule is a draft plan by a Monero (XMR) developer, who labels the document a non-binding working draft. It pencilled in a first fork-enabled release for October 14 to 21, 2026, a fully featured release with hardware wallet and multisig support early in December, and activation in the opening week of March 2027. As of Friday, getmonero.org carries no announcement of a fork-enabled release, and the project's blog said as recently as May 2026 that no fork date had been set; dates in this plan have moved before and can move again. For holders, the planned changes are concrete. Existing standard addresses and subaddresses keep working unchanged, every transaction gains a far larger anonymity set, transactions grow larger on the wire, wallets re-scan the full chain once after the update, and custom unlock times disappear from new transactions. A new addressing protocol called Carrot ships alongside the upgrade: addresses from Carrot wallets look identical to the old ones, and Carrot shields against the Janus address-linking attack and the burning bug. The migration work sits in software, not in addresses, so users update wallets and wait through a single re-scan rather than moving funds anywhere. Market attention has already shown up in derivatives positioning and trading volume: our earlier coverage recorded perpetual futures open interest crossing $300 million for the first time since January, our desk has also carried a warning of a large liquidation event at $287 million in open interest, and veteran trader Peter Brandt's chart comparison of the Monero (XMR) structure against silver's run toward $125 keeps the asset on watchlists. Holders who want to tighten habits before a fork arrives can start with a guide on how to use Monero, and anyone running infrastructure should weigh the network-layer privacy tool Kovri, which routes node traffic over I2P so a remote operator cannot log the originating IP address.

The Limit FCMP++ Does Not Touch

Our reading of the draft plan is straightforward: this is a chain-level change, and its guarantees stop at the chain. Node operators should plan for larger transactions, wallet maintainers for a one-time re-scan, and everyone for an activation window near March 2027 that stays a draft figure until getmonero.org publishes a fork-enabled release. The anonymity set widens from 16 candidates to the entire spendable supply, yet every traceability channel outside the ledger keeps operating exactly as before: exchange accounts tied to an identity, remote nodes logging IP addresses, and mirror-image payments between the same two parties. FCMP++ redraws what the ledger can reveal; it says nothing about how a user acquires, stores or transmits coins, and that is where most real-world tracing still starts. Readers tracking levels around the current pullback can follow our Monero technical analysis.