Grin: private electronic cash built on Mimblewimble
Protocol by
“Tom Elvis Jedusor” (pseudonym, identity unknown), author of the Mimblewimble paper, 2016
Grin started by
“Ignotus Peverell” (pseudonym), 2016
Mainnet
15 January 2019
Status
Running. No pre-mine, no ICO, no founder’s reward.
Grin: money with no amounts and no addresses on chain.
Grin is a privacy-focused cryptocurrency using the Mimblewimble protocol. It was described by an anonymous author, started by a pseudonymous developer, and is kept running by ordinary people. This file explains it from the start, no background needed.
Your balance is none of anyone’s business. There are no amounts and no addresses on the chain, so nobody can look up your balance on the chain: not , not . Exchanges and hosted wallets you use still see what passes through them.
Hover, tap or press the black bars to uncover them. On chain, amounts stay hidden.
Mimblewimble is a way to build a blockchain that hides amounts, writes no addresses, and throws away spent coins. Grin is a minimal implementation of it.
Origin
Paper by the pseudonymous “Tom Elvis Jedusor” (Voldemort’s name in the French Harry Potter books), dated 19 July 2016. It was posted anonymously to the #bitcoin-wizards IRC channel as a text file on a Tor (.onion) server on 2 Aug 2016 (UTC; 1 Aug in US time zones).
Andrew Poelstra published a follow-up paper with refinements in October 2016.
Grin
Ignotus Peverell announced Grin, a minimal implementation, on 20 Oct 2016; mainnet followed on 15 Jan 2019. Igno stepped away a few months after launch (last commit April 2019).
Status
Active. Mainnet since 15 January 2019. Open source since 2016.
Core properties
No addresses on chain. Sender and receiver build each transaction together by passing a “slatepack” (a block of text) by copy-paste, file, QR, or automatically over Tor. Wallets also give you a slatepack address you can share, but it is never written to the chain: it only encrypts and routes that exchange.
Hidden amounts: each amount is locked inside a cryptographic commitment (Confidential Transactions, using Pedersen commitments, plus Bulletproof range proofs that show no amount is negative).
Cut-through drops spent outputs, so the chain keeps only unspent outputs, block headers and a small kernel per transaction (a tiny signature proving the transaction is valid).
No scripting language: a small, fixed set of transaction kinds.
Linear emission: 60 GRIN per minute, forever.
A-1 · Ownership
No company
No company, no foundation, no pre-mine. Development is funded by donations.
A-2 · Privacy
Private by default
No amounts and no addresses on chain. Transactions in a block merge together, which makes them harder to link, but an observer running many nodes can still link many of them. Grin reduces linkability; it does not remove it.
A-3 · Size
A small chain
Cut-through keeps the chain small: a pruned node needs only a few gigabytes.
A-4 · Launch
Fair launch
No ICO, no airdrop, no venture backing. 60 GRIN per minute, the same forever.
Exhibit B · ProcedurePage 3 of 13
How Grin works, in four steps
A Grin payment is a short conversation between two wallets, then a block that hides what it can and forgets what it no longer needs.
Build it together
Sender and receiver build each transaction interactively. No address is ever written on chain: the wallets exchange a “slate” (as text, a slatepack) to build a joint signature. A slatepack address, if you use one, only routes and encrypts that exchange.
Hide the amount
Amounts are hidden using Confidential Transactions (Pedersen commitments). Only sender and receiver know the value transferred.
Relay and merge
A new transaction is first passed through a few peers (a Dandelion++ variant) to make it harder to tell where it came from. In a block, transactions are merged by CoinJoin-style aggregation (many transactions combined into one), which makes individual transactions harder to trace.
Cut through
Spent outputs are cut through. What is left is the unspent outputs, the block headers, and one small kernel per transaction, so the chain grows far more slowly than the transaction history.
Exhibit C · FindingsPage 4 of 13
How Grin compares: nine findings
Time-backed monetary policy
60 GRIN are minted on average every 60 seconds, forever. No halving shock, no supply cliff: every block pays the same 60 GRIN in 2019 and in 2099. One minute of network time equals 60 new coins, so the supply is as predictable as a clock.
Privacy on chain, honestly stated
No addresses and no amounts are ever written to the blockchain. Which outputs were spent together can often be worked out by someone watching the network with many nodes. Grin reduces this linkability; it does not remove it.
Compared with gold: checkable in digital form
Nobody can audit the world’s gold supply, and tokenized gold depends on trusting a custodian. Grin’s supply is mathematically verifiable by anyone running a full node: every node checks that the hidden amounts add up to the known emission. No custodian required.
Compared with USD-pegged coins: no decree
Fiat-backed stablecoins import their central bank’s monetary policy. Grin’s emission is fixed in the consensus rules. Changing it would take a hard fork (a rule change every node must upgrade to) that node operators would have to choose to run, and there is no company or foundation to decree one.
Compared with Bitcoin: a reward that keeps paying
Bitcoin’s 21 million cap means that once the last coin is mined, miners rely entirely on transaction fees. Whether that keeps the network secure is an open economic question. Grin’s constant block reward keeps paying miners.
A small footprint
Since 2019 the chain has stayed compact: spent outputs are cut through, so a pruned node stays small.
Emission for generations
With a fixed reward and a growing supply, the inflation rate approaches zero over time, with no hard stops or abrupt halvings. Annual inflation is about 13% in late 2026 and falls every year. No coins were set aside for insiders.
Simple and open source
A deliberately minimal protocol. No proprietary components, no hidden supply curves, no pre-allocated coins. Open source since 2016.
Time cannot be copied (our opinion)
We think this is what makes Grin hard to replicate: anyone can fork the code, but a fork resets the clock. The proof-of-work mined since 2019 cannot be mined again.
Exhibit D · Known usesPage 5 of 13
What people use Grin for
Peer to peerDirect payments between individuals, no intermediary
MicropaymentsSmall payments with low fees
Online shoppingPrivate online payments: amounts and addresses never appear on chain
RemittancesInternational transfers person to person, with no bank in between
PrivacyAmounts and addresses stay off the chain
PredictabilityKnown emission: anyone can compute supply at any block
Point of saleMerchant tools exist (for example GoblinPay, a self-hostable payment server that receives Grin)
Financial freedomCensorship-resistant, permissionless, no gatekeeper
Instructions · For the new recruitPage 6 of 13
Start using Grin
Three steps: a wallet, a first few grin, and, if you like, a node of your own.
Listings change: check current listings before you trade.
Grin is experimental software. Nothing here is financial advice.
Step 03
Run a node
A node checks every rule of the chain for you and helps the network. On a Linux server, Grin Node Toolkit walks you through it from a menu; at home, an Umbrel community app runs one.
Cross-platform wallet app with a built-in node, written in Rust. Android, Linux, macOS, Windows (iOS announced, not out yet as of Nov 2026). Actively developed (v0.3.6, Aug 2026).
A mobile-first payments app built on Grim. Pay a username like [email protected], or a Nostr key. No sign-up: your identity is a Nostr key kept on your device, separate from your wallet seed.
Payments travel as sealed, encrypted messages over Tor built into the app; relays never see the amount. Android, Linux, macOS, Windows (iOS coming, as of Nov 2026).
Open-source Bash toolkit to build and manage Grin nodes, API servers, explorers, wallet services and mining on a Linux server, from one menu. A dozen live demo sites run on it.
Hosted web wallet run by the EasyGrin pool, built for miners collecting pool payouts. Needs an account; you can export your recovery phrase. It is a hosted service, so keep small amounts.
Classic wallet app with a long history in the Grin ecosystem, full node included. Written in C++; Windows, macOS, Linux, Android. Last stable release v1.2.8 (Mar 2023); v1.2.9 pre-release (Oct 2024).
wallet
desktop
android
E-7 · Mining
Mining hardware & pools
iPollo G1 Mini: a dedicated ASIC miner for Grin’s Cuckatoo32 puzzle, about 1.2 graphs/s at about 120 W. A GPU with 8 GB+ VRAM can also mine Cuckatoo32 (more VRAM is better); ASICs now dominate.
One Bash toolkit for a Linux server: full node, pruned node, explorer, public API, mining pool, wallet portal, Nostr relay, all semi-automated. A dozen live demo sites are built with it.
The toolkit has its own home now, with a manual and setup paths for servers, home servers and desktops: grinnode.org.
root@vps: ~
git clone https://github.com/noobvie/Grin-Node-Toolkit
cd Grin-Node-Toolkit
sudo ./grin-node-toolkit.sh
Read from world.grin.money and refreshed every 5 minutes. A dash means the figure has not loaded.
—block height
—GRIN issued so far (60 per block)
—hashrate · graphs per second
—mining difficulty (how hard a block is to find)
—active mainnet nodes · last 30 days
—annual inflation (approx.)
—GRIN/USDT · Gate
—sats per GRIN · CoinGecko (converted)
Evidence log · Newest firstPage 10 of 13
On record
How Grin got here
A hard fork is a rule change every node must upgrade to. Names like Cuckaroo and Cuckatoo are Grin’s mining puzzles.
Jun 2026
v5.5.0 node release (latest v5.5.2, Oct 2026).
2025
The Original and Community councils merged; one community council now holds all funds in a single multisig (a wallet that needs several council members to sign). Council info
Aug 2024
Grim, cross-platform wallet app + node, public release. gri.mw
2024
grincoin.org community block explorer. grincoin.org
Jan 2024
v5.2.0: fast parallel sync (PIBD) on mainnet for new nodes.
May 2021
Community Council formed; seeded with 33 BTC from the development fund that September.
Jan 2021
v5.0.0, 4th and last scheduled hard fork (block 1,048,320): ASIC-resistant proof-of-work retired (Cuckatoo32+ only), new difficulty algorithm, fixed fees; wallet sends over Tor/Slatepack instead of HTTP.
Earlier entries, 2016 to 2020 (8)
Jul 2020
v4.0.0, 3rd hard fork (block 786,240): proof-of-work changed to Cuckarooz29; the wallet introduces Slatepack.
Jan 2020
v3.0.0, 2nd hard fork (block 524,160): proof-of-work changed to Cuckaroom29; the wallet adds Tor sending and payment proofs.
Oct 2019
Coinspect security audit published (node + wallet), all findings fixed.
Jul 2019
v2.0.0, 1st hard fork (block 262,080): proof-of-work Cuckaroo29 changed to Cuckarood29.
15 Jan 2019
Mainnet launch. Fair for all. Time starts now.
20 Oct 2016
Ignotus Peverell announces Grin, a minimal implementation, in #bitcoin-wizards.
Oct 2016
Andrew Poelstra publishes a follow-up paper with refinements.
Aug 2016
The Mimblewimble paper by “Tom Elvis Jedusor” (dated 19 July) appears in #bitcoin-wizards as a text file on a Tor server.
Wanted · Open positionsPage 11 of 13
Recruiting
Talents needed
Grin is a small, passionate community building a technically rigorous privacy protocol. No foundation, no VC, no boss. Pure open-source meritocracy: every contribution counts.