What is MWEB?
GUIDE · 8 MIN READ
What is MWEB?
MWEB is the optional privacy layer that activated on Litecoin in May 2022. It brings confidential transactions — hidden amounts, unlinked addresses — as a per-transaction choice. Here's the full picture.
What is MWEB?
MWEB stands for MimbleWimble Extension Block. It's an extension to the Litecoin protocol that activated in May 2022, adding a second 'lane' to the chain: an optional privacy-focused extension block that runs alongside the main Litecoin ledger. The key property: transactions inside MWEB have confidential amounts and unlinked addresses. An observer looking at the chain can see that an MWEB transaction happened, but cannot see how much was sent or which addresses sent and received it. MWEB is not a separate coin. The LTC moving through MWEB is the same LTC as the rest of the chain — users peg in from the standard ledger to MWEB, transact privately, and peg back out when they want to return to the standard ledger. The 84 million LTC supply cap applies to both the standard ledger and MWEB combined.
MimbleWimble origins
MimbleWimble is a cryptocurrency protocol first described in a July 2016 anonymous whitepaper posted to a Bitcoin research IRC channel under the name Tom Elvis Jedusor — French for 'Tom Marvolo Riddle', a Harry Potter reference. The protocol solved a long-standing problem: how to have confidential transaction amounts and unlinkable addresses without bloating the chain. The MimbleWimble approach uses Pedersen commitments (cryptographic blobs that hide values while proving inputs equal outputs) and aggregated transactions (many transactions inside a block merge into one combined blob, further obscuring individual sends). Two standalone cryptocurrencies implemented MimbleWimble as their base protocol: Grin (launched January 2019) and Beam (launched January 2019). Both are privacy-focused proof-of-work chains with no visible amounts or addresses. MWEB on Litecoin takes a different approach: MimbleWimble as an optional extension rather than as the entire chain. This gives Litecoin users the choice — standard Litecoin for transparent transactions, MWEB for confidential ones — and avoids the privacy-ecosystem tradeoffs that a fully private chain like Monero or Grin faces with exchange listings.
How MWEB works
Pedersen commitments hide amounts
Every MWEB output uses a Pedersen commitment — a cryptographic value that binds to an amount without revealing it. The chain enforces that inputs sum to outputs (no money is created or destroyed) using the math of the commitments, without ever exposing the numeric values. An observer sees 'input commitment A and input commitment B produce output commitments C and D' — valid arithmetic, but the actual numbers stay hidden.
One-time addresses unlink senders and receivers
MWEB addresses are derived per-transaction from a view key and a spend key. The sender generates a fresh one-time address for each payment using the recipient's view key; the recipient can scan the chain to find their outputs. The same 'mailing address' is never reused on-chain, so a recipient's balance cannot be clustered by observing incoming transactions to a single public address.
Transaction aggregation reduces footprint
Inside a block, multiple MWEB transactions merge into one aggregated transaction. Individual input-output mappings disappear into the aggregate. This reduces on-chain storage and — importantly — makes it harder to trace specific transactions through the block, even cryptographically.
Kernels prove validity
Each MWEB transaction emits a 'kernel' — a small public proof that the transaction was valid, signed by the sender, with the transaction fee declared. Kernels stay permanently visible on-chain; they are what lets every node verify the chain without revealing amounts or parties.
Peg-in and peg-out
MWEB is a separate block from the standard Litecoin ledger. To move LTC from one to the other, users execute a peg-in (standard → MWEB) or a peg-out (MWEB → standard). A peg-in is a normal Litecoin transaction that sends LTC to a special MWEB deposit address. The chain recognizes this as a peg-in, credits the sender's MWEB balance, and removes the LTC from the standard ledger. A peg-out is the reverse: a user burns MWEB balance and receives standard-ledger LTC at a destination address. Both peg operations are visible on the standard ledger — an observer sees 'wallet X pegged 1 LTC into MWEB at time T' or 'wallet Y received 1 LTC from an MWEB peg-out at time T'. What happens inside MWEB between the peg-in and peg-out is confidential. To make peg operations less linkable, users can delay between peg-in and peg-out, peg out to a different address than they pegged in from, and split or combine amounts across multiple pegs.
Activation history
MWEB was proposed in 2019 by David Burkett, who led the implementation. Two Litecoin Improvement Proposals formalized the work: LIP-0002 defined MWEB itself, and LIP-0003 defined the soft-fork activation mechanism. The soft fork required miner signaling: once a threshold of blocks signaled support, MWEB would lock in and activate after a grace period. Signaling began in 2021. The lock-in threshold was hit, and MWEB activated on Litecoin mainnet at block 2,257,920 on May 20, 2022 — roughly two and a half years after the original proposal. MWEB was the first major confidentiality upgrade to a top-tier proof-of-work chain with Litecoin's operational history. Bitcoin has proposed similar upgrades (Taproot's partial privacy enhancements, various Confidential Transaction proposals) but has not activated an equivalent as of 2026.
Wallets supporting MWEB
MWEB requires wallet-side support — your wallet needs to understand MWEB addresses, generate peg-in/peg-out transactions, and scan for MWEB balances. As of 2026, the main wallets supporting MWEB are: Lite Wallet (every platform — Windows, macOS, Linux, iOS, Android); Cake Wallet (macOS, Linux, iOS, Android — no Windows); Litecoin Core (recent versions, desktop only). Electrum-LTC does not currently support MWEB. Most multicoin wallets (Exodus, Trust Wallet, Atomic, Coinbase Wallet) do not support MWEB — they treat Litecoin as a standard-ledger-only asset. If you want MWEB specifically, choose a wallet from the supporting list above. Lite Wallet is the most complete in terms of platform coverage.
What MWEB doesn't do
MWEB makes transactions inside the extension block confidential — amounts and addresses are hidden there. It does not hide peg-in and peg-out events, which remain visible on the standard Litecoin ledger. An observer can see that wallet X pegged 1 LTC into MWEB at 10:00 AM and that wallet Y received 1 LTC from an MWEB peg-out at 10:15 AM — and with high confidence, link those two events. For maximum privacy, delay between peg-in and peg-out, peg out to a different address, and break up amounts. MWEB is a meaningful privacy upgrade; it is not perfect anonymity.