When cryptocurrencies dance with regulation, Monero still stubbornly defaults to privacy. The FCMP++ upgrade elevates the anonymous set from 16 to 150 million and features forward secrecy, safeguarding historical privacy even against quantum threats.
(Background: Privacy coins surge! Silicon Valley investor Naval Ravikant’s comment sent Zcash soaring 200% in ten days)
(Additional context: Privacy coin $ZEC skyrocketed sixfold in a month—what’s fueling this frenzy?)
Table of Contents
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- Two Clouds Over BTC
- Security Budget Issues
- Threats from Quantum Computing
- XMR Facing Quantum Threats: A More Severe Challenge Than BTC
- Deep Dive into FCMP++: Monero’s Cryptographic Leap
- Not Just Increasing Ring Size, But Replacing the Entire Privacy Framework
- Separating Membership Proof and Spend Authorization
- Forward Secrecy: Hackers Can Steal Money with Quantum Computers, But Cannot Steal Privacy
- Outgoing View Key: Making “See the Spend” Possible Without “Being Able to Spend”
- Transaction Chaining: Enabling Lightning Network on XMR
- Same Address, Seamless Upgrade
- Academic Origins of FCMP++: A Tribute to Firo
- Conclusion: An Unfinished Revolution, Eternal Crypto Punk Spirit
For some reason, I find myself revisiting Monero every few years, and each time I fall deeper in love with it.
Perhaps it’s because, as the entire crypto world becomes more accustomed to dancing with regulation, shaking hands with Wall Street, and feeding each other narratives of compliance through various institutions, Monero still stubbornly clings to one very old, yet especially precious principle: making privacy the default, not an option. Or perhaps it’s because Monero inherits the purest crypto punk spirit—privacy technology and grassroots community.
For crypto punks, the real test is suppression at the level of sovereign states. XMR has been delisted from major exchanges like Binance and OKX in 2024, and faces bans in various countries, yet it still endures—trading volume continues to rise (see TRM Labs report). Confronting Leviathan rather than cooperating—that’s the heart of crypto punk. Are ETF and digital asset regulation frameworks cause for celebration? No, that’s surrender, not revolution. Do you want assets that are easily absorbed into the financial system and transparent, or truly digital cash belonging to the people?
Satoshi’s vision was “peer-to-peer electronic cash,” and I see BTC as an unfinished revolution. The crypto punk manifesto states:
“Privacy is an indispensable element of an open society in the digital age.”
Hal Finney, as early as 1993, wrote Protecting Privacy with Electronic Cash, exploring how cryptography could restore the anonymity of cash in the digital world. Cash must be anonymous—that’s core to Monero. Forcing the hiding of recipients, senders, and amounts—no compromise.
In 2020, I wrote a review of Monero, and in 2021, I discussed the censorship resistance issues of BTC. Over the years, I am even more convinced that my initial intuition was correct: privacy is not just a feature of blockchain; it is the fundamental prerequisite for digital cash to exist.
Two Clouds Over BTC
Beyond privacy, I see two long-term clouds over BTC: the rigid decline of security budget due to halving cycles and the threat of quantum computing exposing public key addresses.
Security Budget Issues
Bitcoin’s block subsidy halves periodically—a well-known monetary policy design; but this also means that the protocol’s new reward for miners decreases mechanically, and the system will increasingly rely on rising coin prices or transaction fees to maintain security. For believers, this may seem trivial, but it’s a wish, not a plan. Especially with BTC’s wavering attitude towards non-monetary uses like OP_RETURN and the ongoing failure to build a robust on-chain ecosystem, I see the security budget problem as unresolved since 2017.
Monero’s pragmatic solution is tail emission: since June 2022, it produces a fixed 0.6 XMR every two minutes forever. Nearly four years in, hash rate remains stable, and the network continues to resist ASIC dominance through the RandomX algorithm, allowing mining decentralization on ordinary CPUs.
BTC and XMR’s total supply will roughly cross around 2040—then we’ll see if BTC can find a way to solve its security budget issue after multiple halvings. All words are hollow without proof; let history be the witness.
I’ve always believed that BTC’s three core design elements—UTXO > PoW > 21 million—are brilliantly crafted, yet it’s ironic that the most coarse-grained design, the fixed supply cap, has become the core of religious dogma… The least theological number has become the most untouchable doctrine.
Threat of Quantum Computing
BTC will inevitably face the governance issue of early P2PK (Pay-to-Public-Key) addresses—millions of BTC, including Satoshi’s addresses. Many prefer to ignore this, but it won’t just disappear because everyone looks away. Even if new address formats are introduced, a decision must be made at some point: freeze early addresses including Satoshi’s, or allow early holders to move their coins first. It’s akin to defining ownership rights over sunken treasure before the invention of submarines—an unresolvable governance dilemma.
XMR Facing Quantum Threats: A More Severe Challenge Than BTC
For XMR, the quantum threat is even more severe. Privacy coins must worry not only about quantum computers stealing funds, but also about decrypting the entire transaction history. Yes, currently, XMR’s ring signatures could theoretically be broken by sufficiently powerful quantum computers—attackers could trace which output is real within a ring, reconstructing the transaction graph. If a privacy chain’s history can be unraveled after ten or twenty years, then it’s not truly private but only temporarily obscured.
The XMR community is not passive. The planned FCMP++ (Full-Chain Membership Proofs++) in 2026 aims to be Monero’s most significant cryptographic upgrade, fundamentally strengthening privacy and making transactions immune to quantum attacks. (Currently in alpha testnet phase)
Deep Dive into FCMP++: Monero’s Cryptographic Leap
Not Just Increasing Ring Size, But Replacing the Entire Privacy Architecture
Current status: each XMR transaction uses a ring size of 16—your real output mixed with 15 decoys, making it impossible for outsiders to determine which is genuine. This provides 1/16 anonymity, which is strong in practice, but as analysis tools improve and spam attacks increase, fixed-size anonymity sets could weaken over time.
The core revolution of FCMP++ is replacing ring signatures with full-chain membership proofs. After the upgrade, each transaction will be mixed not just with 15 decoys but with all unspent outputs (UTXOs) on the chain. Based on early 2026 estimates, this means the anonymity set jumps from 16 to over 150 million—roughly ten million times larger.
How? FCMP++ employs curve trees—a structure based on elliptic curve cryptography, similar to Merkle trees but designed for zero-knowledge proofs. It leverages elliptic curve cycles to generate compact proofs, so even with full-chain coverage, proof size remains logarithmic (around 2-3 KB), and verification takes milliseconds.
Separating Membership Proof and Spend Authorization
More fundamentally, FCMP++ splits the functions previously handled by ring signatures into independent cryptographic components:
Layer 1: Membership Proof—Proves “this output exists on the chain and is unspent.” This is the full-chain proof covering all UTXOs.
Layer 2: Spend Authorization—Proves “I have the right to spend this output.” Uses separate key pairs X, Y.
The key insight: in FCMP++, private keys are split into two parts, X and Y. The linking tag that prevents double-spending is associated only with private key X, while spend authorization requires both X and Y. This separation yields several fascinating properties:
Forward Secrecy: Hackers Can Steal Money with Quantum Computers, But Cannot Steal Privacy
This is one of FCMP++’s most exciting cryptographic features. Suppose, in the future, quantum computers can solve elliptic curve discrete logarithm problems (ECDLP). Attackers might forge valid spend proofs to steal unspent funds—yet they still cannot determine who initiated past transactions or trace the chain’s history. Because the membership proof structure is designed so that even if the underlying math is broken, it cannot be used to backtrack which outputs corresponded to real spenders.
In other words: FCMP++’s upgraded transaction history has forward secrecy. Transactions made in 2026, even with mature quantum computers in 2040, will still preserve the privacy of past data. (Of course, unspent outputs remain vulnerable to quantum theft, which may require future upgrades to post-quantum cryptography—yet, at least, privacy remains intact.)
Outgoing View Key: Making “See the Spend” Possible Without “Being Able to Spend”
Because the linking tag depends only on private key X, FCMP++ allows you to publicly share this key so third parties can track your spending flow but cannot spend on your behalf (lacking Y). This provides flexible transparency for audits, compliance, and charity transparency—allowing you to prove fund flows without revealing full spending authority. Wallet UX can be optimized for this, reducing the need to expose sensitive keys. The official team even suggests that defining a single “view key” in the future will be more natural, without rigidly separating incoming/outgoing.
Transaction Chaining: Enabling Lightning Network on XMR
Because membership proofs can be registered on-chain independently of spend authorizations, a revolutionary possibility emerges: two users can first register a 2-of-2 multisig membership proof on-chain, then conduct off-chain exchanges, and finally broadcast the spend authorization to settle. This is transaction chaining—opening the door for payment channels (similar to Lightning Network) on Monero. Historically, XMR lagged behind BTC in Layer 2 scaling due to privacy architecture constraints. FCMP++ changes that. It signifies that Monero is no longer just “on-chain privacy,” but can extend privacy into more interactive payment designs.
Same Address, Seamless Upgrade
Importantly, FCMP++ maintains excellent backward compatibility: existing Monero addresses remain valid forever. Users don’t need to generate new wallets or transfer funds. Old addresses continue to receive payments, while new privacy protections are automatically enabled at the protocol level. Monero allows wallets to gradually adopt features like outgoing view keys and forward secrecy at their own pace, without forcing immediate overhaul.
Academic Origins of FCMP++: A Tribute to Firo
Finally, the cryptographic inspiration behind FCMP++ traces back to the lineage of privacy coins. Monero’s next-generation protocol Seraphis (the foundation of FCMP++) has deep roots in Firo (formerly Zcoin) and its Lelantus Spark protocol. FCMP++ pushes further—employing curve trees to extend anonymous sets to the entire chain, surpassing Spark’s original limit of about 65,000 in anonymity set size.
FCMP++ has undergone independent security audits by Veridise (2025). By early 2026, alpha stress test networks are live, subjecting the protocol to community testing. This is Monero’s boldest cryptographic operation in over a decade—replacing core privacy mechanisms on a vibrant, multi-billion-dollar blockchain.
Conclusion: An Unfinished Revolution, Eternal Crypto Punk Spirit
The crypto punk manifesto states clearly:
“Privacy is an indispensable element of an open society in the digital age.”
Satoshi created a scarce asset without central issuance—great indeed; but if we truly believe in “digital cash,” a system that only offers transparent transfers but lacks default privacy remains an incomplete revolution. BTC may become the new gold—resistant to inflation, regulated, held by institutions. But I believe the true mission of crypto—freedom—should not end there.
Monero is forging a more arduous, yet more faithful path to its crypto punk roots. FCMP++ is not just a technical upgrade; it’s the latest embodiment of crypto punk spirit at the cryptographic frontier. Monero fights surveillance with mathematics, opposes Leviathan with grassroots, counters security budget uncertainties with tail emission, and defies future quantum threats with forward secrecy.
If this upgrade succeeds, Monero will not only remain the king of privacy but elevate it to a level previously only theoretical—a state where even nation-states cannot statistically de-anonymize the set.
This is the promised land of crypto punk.
