Verify a decision

{"actor":"system:backfill","investigation_id":"acbf7d40-7b57-4717-869d-bcf63a1d1f69","kind":"publish","page_slug":"taiko","published_at":"2026-06-27T17:13:37.956Z","sequence_num":1,"snapshot":{"content_type":"investigation","entity_name":"Taiko","sections":[{"content":"Taiko is a decentralized, Ethereum-equivalent Layer 2 rollup built by Taiko Labs. It uses a Based Contestable Rollup (BCR) architecture in which Ethereum validators also act as Taiko sequencers, removing the need for a centralized sequencer. The protocol employs ZK-EVM technology and targets full EVM equivalence so that existing Ethereum smart contracts and tooling can be deployed without modification. Taiko's multi-proof system, branded Raiko, was designed to combine Intel SGX attestations with ZK backends including SP1 and RISC0, requiring multiple independent proof types to validate state transitions. According to L2BEAT, as of June 2026 the protocol holds a Stage 0 classification — meaning it does not yet meet Stage 1 decentralization requirements — with sequencing gated by a whitelist of one active operator and proving gated by a ProverWhitelist of two whitelisted provers.","heading":"Protocol Overview","severity":"medium","sources":[{"credibility":2,"name":"Taiko Alethia — L2BEAT Risk Assessment","type":"research","url":"https://l2beat.com/scaling/projects/taiko"},{"credibility":2,"name":"What is Taiko? — Taiko Official","type":"official","url":"https://taiko.xyz/guides/what-is-taiko-blockchain"},{"credibility":2,"name":"Taiko — The True Ethereum L2 (Gate Learn)","type":"other","url":"https://www.gate.com/learn/articles/taiko-the-true-ethereum-l2/4158"}]},{"content":"On June 22, 2026, an attacker drained approximately $1.7 million from Taiko's L1 Bridge (contract 0xd60247c6848B7Ca29eDdF63AA924E53dB6Ddd8EC) and ERC20Vault (contract 0x996282cA11E5DEb6B5D122CC3B9A1FcAAD4415Ab) on Ethereum mainnet. Security firm BlockSec identified the root cause as an RSA-3072 private key file named enclave-key.pem committed to the public taikoxyz/raiko GitHub repository. Raiko uses Intel SGX enclaves to generate cryptographic attestations that Taiko's L1 bridge contracts accept as proof that L2 state transitions are valid. With the private key publicly accessible, the attacker enrolled their own SGX prover, signed fraudulent L2 state attestations, and caused the on-chain verifier to treat them as legitimate by exploiting the MrSigner trust model. The attack proceeded in two phases: forged attestations triggered processMessage() calls that set withdrawal statuses to RETRIABLE, and retryMessage() then executed with minimal additional checks, releasing funds that had no corresponding MessageSent events on Taiko's source chain. The attacker subsequently moved approximately 1.99 million TAIKO tokens (worth roughly $170,000–$189,000 at the time) to an address on the MEXC exchange before the bridge freeze took effect. Four attacker wallet addresses were disclosed by Taiko: 0x7506DeA0c38ca0B55364B22424374c5A1ae1B76a, 0x5fbc60a12bc6635e7d587d8dac52e4b1388b4990, 0x3cc936b795a188f0e246cbb2d74c5bd190aecf18, and 0x9108828e30f2de407aadb0af677b4a9228e4acd4.","heading":"June 2026 Bridge Exploit — SGX Key Exposure","severity":"critical","sources":[{"credibility":2,"name":"Taiko Bridge Drained $1.7M After SGX Signing Key Left Exposed on GitHub — The Defiant","type":"news_article","url":"https://thedefiant.io/news/hacks/taiko-bridge-exploit-sgx-signing-key-github-1-7m"},{"credibility":2,"name":"Taiko halts its Ethereum layer-2 network after a bridge exploit, token dives 10% — CoinDesk","type":"news_article","url":"https://www.coindesk.com/tech/2026/06/22/taiko-halts-its-ethereum-layer-2-network-after-a-bridge-exploit-token-dives-10"},{"credibility":2,"name":"$1.7M Gone: Taiko Bridge Exploited After SGX Signing Key Leak — Crypto Times","type":"news_article","url":"https://www.cryptotimes.io/2026/06/22/1-7m-gone-taiko-bridge-exploited-after-sgx-signing-key-leak/"},{"credibility":2,"name":"Taiko Bridge Exploit: How a Leaked Key Drained $1.7M — Thirdweb Blog","type":"research","url":"https://blog.thirdweb.com/taiko-bridge-exploit-explained-how-a-leaked-key-led-to-1-7m-in-forged-withdrawals/"},{"credibility":1,"name":"Taiko Bridge: Etherscan Contract","type":"on_chain","url":"https://etherscan.io/address/0xd60247c6848b7ca29eddf63aa924e53db6ddd8ec"},{"credibility":2,"name":"Ethereum L2 Bridge Exploit Drains $1.7M — TechTimes","type":"news_article","url":"https://www.techtimes.com/articles/318886/20260623/ethereum-l2-bridge-exploit-drains-17m-leaked-sgx-key-defeats-taiko-trust-model.htm"}]},{"content":"Within hours of detecting the exploit, Taiko's Security Council activated its 7-of-9 multisig to pause bridge withdrawals and halt block production network-wide. The team published the four attacker wallet addresses publicly and requested centralized exchanges, including MEXC, suspend TAIKO token deposits. By approximately 2:08 AM ET on June 22, the incident was contained. Taiko pledged that no user funds would be lost, committing to fully recollateralize the bridge to 1:1 backing before reopening. As of a June 25 update, the team reported it was in the testing phase of necessary repairs but provided no specific reopening date. The CEO filed a formal report with Singapore authorities and pledged cooperation with law enforcement investigators. Four pull requests labeled respond-to-hack were merged into the Taiko codebase within 24 hours of the exploit, with PR #21820 described as porting hack recovery hooks to v3 to address the signing infrastructure. A detailed technical post-mortem had not yet been published as of the most recent reporting.","heading":"Incident Response and Recovery","severity":"high","sources":[{"credibility":2,"name":"Taiko to Fully Restore Bridge Backing After $1.7M Hack — Crypto Times","type":"news_article","url":"https://www.cryptotimes.io/2026/06/25/taiko-to-fully-restore-bridge-backing-after-1-7m-hack/"},{"credibility":2,"name":"Taiko Hack Forces Bridge Withdrawal Warning Amid $1.7M Incident — Bitcoin Foundation","type":"news_article","url":"https://bitcoinfoundation.org/news/blockchain-news/ethereum-l2-taiko-hack-forces-bridge-warning-amid-1-7m-exploit/"},{"credibility":2,"name":"Taiko urges users to exit bridges after a verification flaw was exposed — MEXC News","type":"news_article","url":"https://www.mexc.com/news/1163847"},{"credibility":3,"name":"Taiko Bridge Exploit June 2026 — SpotedCrypto","type":"news_article","url":"https://www.spotedcrypto.com/taiko-bridge-exploit-june-2026/"}]},{"content":"According to L2BEAT's June 2026 assessment, Taiko is classified as Stage 0 — the lowest tier — because it does not yet meet Stage 1 decentralization requirements. Key risks flagged include: (1) the absence of a functional proof system during the post-exploit emergency period, meaning the protocol fully relies on a single entity to safely update state; (2) no user exit window, as contracts are instantly upgradeable with no enforced delay; (3) sequencing performed by a whitelist with only one active operator, with permissionless sequencing only available after a 1-day, 1-hour delay; and (4) proving gated by a ProverWhitelist with two whitelisted provers, with permissionless proving available only after five days of unproven proposals. The Security Council holds a 7-of-9 multisig that can execute emergency proposals instantly, bypassing normal governance delays. TAIKO token concentration is also flagged, with 80.2% of total value secured represented by the TAIKO token itself. Additionally, a separate vulnerability in SP1/Plonky3 — a dependency of Taiko's ZK proving backend — was publicly disclosed in early 2025 and patched; Taiko's multi-proof architecture was credited with mitigating the impact of that earlier issue.","heading":"Security Architecture and Centralization Risks","severity":"high","sources":[{"credibility":2,"name":"Taiko Alethia — L2BEAT","type":"research","url":"https://l2beat.com/scaling/projects/taiko"},{"credibility":2,"name":"Succinct's SP1 bug sparks transparency debate in ZK security — Blockworks","type":"news_article","url":"https://blockworks.co/news/succinct-sp1-bug"}]},{"content":"Taiko Labs was founded in March 2022 by Daniel Wang, who previously founded Loopring, the first ZK proof-based decentralized exchange protocol on Ethereum, in 2017. Wang holds degrees from the China University of Science and Technology and Arizona State University and worked previously as a senior software engineer at Google, senior director of engineering at JD.com, and senior director at Zhongan Insurance. Taiko raised a total of $37 million across three rounds: a seed round and a $15 million Series A closed on March 2, 2024, led by Lightspeed Faction, Hashed, Generative Ventures, and Token Bay Capital, with participation from Wintermute Ventures, Presto Labs, Flow Traders, Amber Group, OKX Ventures, GSR, and WW Ventures. The TAIKO token launched on June 5, 2024, with a total supply of 1 billion tokens. A genesis airdrop allocated up to 5% of supply (50 million tokens) to over 300,000 community members who had interacted with Taiko testnets, with claims open until July 5, 2024. The protocol launched on Ethereum mainnet on May 27, 2024, with Vitalik Buterin submitting the inaugural block.","heading":"Funding, Team, and Background","severity":"low","sources":[{"credibility":1,"name":"Taiko Raises US$37M from Top-tier VCs Ahead Of Mainnet Launch — PRNewswire","type":"news_article","url":"https://www.prnewswire.com/news-releases/taiko-raises-us37m-from-top-tier-vcs-ahead-of-mainnet-launch-302077780.html"},{"credibility":2,"name":"Daniel Wang — Co-Founder & CEO @ Taiko Labs — Crunchbase","type":"other","url":"https://www.crunchbase.com/person/daniel-wang-4"},{"credibility":2,"name":"Ethereum Layer 2 Taiko announces genesis airdrop ahead of mainnet — The Block","type":"news_article","url":"https://www.theblock.co/post/296168/ethereum-layer-2-taiko-announces-genesis-airdrop-ahead-of-mainnet"},{"credibility":2,"name":"Ethereum Layer 2 Taiko goes live on mainnet — The Block","type":"news_article","url":"https://www.theblock.co/post/296831/ethereum-l2-taiko-mainnet"}]},{"content":"The TAIKO token (ticker: TAIKO) launched on June 5, 2024 with a total supply of 1 billion tokens. As of post-exploit reporting in June 2026, the token carried a market capitalization of approximately $14.5 million and was trading around $0.07–$0.09. Following disclosure of the June 22, 2026 exploit, TAIKO declined more than 10% from its midnight UTC price, with some reports citing a decline exceeding 20% in the hours after announcement. As of the L2BEAT assessment, TAIKO represents 80.2% of total value secured on the protocol, creating significant concentration risk. The attacker moved approximately 1.99 million TAIKO tokens to MEXC prior to the bridge freeze, worth roughly $170,000–$189,000 at the time.","heading":"Token and Market Impact","severity":"medium","sources":[{"credibility":2,"name":"Taiko halts its Ethereum layer-2 network after a bridge exploit, token dives 10% — CoinDesk","type":"news_article","url":"https://www.coindesk.com/tech/2026/06/22/taiko-halts-its-ethereum-layer-2-network-after-a-bridge-exploit-token-dives-10"},{"credibility":2,"name":"Taiko price today, TAIKO to USD — CoinMarketCap","type":"other","url":"https://coinmarketcap.com/currencies/taiko/"},{"credibility":2,"name":"Taiko Alethia — L2BEAT TVS Breakdown","type":"research","url":"https://l2beat.com/scaling/projects/taiko/tvs-breakdown"}]}],"sources_used":[{"credibility":2,"name":"Taiko Bridge Drained $1.7M After SGX Signing Key Left Exposed on GitHub — The Defiant","type":"news_article","url":"https://thedefiant.io/news/hacks/taiko-bridge-exploit-sgx-signing-key-github-1-7m"},{"credibility":2,"name":"Taiko halts its Ethereum layer-2 network after a bridge exploit, token dives 10% — CoinDesk","type":"news_article","url":"https://www.coindesk.com/tech/2026/06/22/taiko-halts-its-ethereum-layer-2-network-after-a-bridge-exploit-token-dives-10"},{"credibility":2,"name":"$1.7M Gone: Taiko Bridge Exploited After SGX Signing Key Leak — Crypto Times","type":"news_article","url":"https://www.cryptotimes.io/2026/06/22/1-7m-gone-taiko-bridge-exploited-after-sgx-signing-key-leak/"},{"credibility":2,"name":"Taiko Bridge Exploit: How a Leaked Key Drained $1.7M — Thirdweb Blog","type":"research","url":"https://blog.thirdweb.com/taiko-bridge-exploit-explained-how-a-leaked-key-led-to-1-7m-in-forged-withdrawals/"},{"credibility":2,"name":"Taiko to Fully Restore Bridge Backing After $1.7M Hack — Crypto Times","type":"news_article","url":"https://www.cryptotimes.io/2026/06/25/taiko-to-fully-restore-bridge-backing-after-1-7m-hack/"},{"credibility":2,"name":"Taiko Alethia — L2BEAT","type":"research","url":"https://l2beat.com/scaling/projects/taiko"},{"credibility":2,"name":"Taiko Alethia TVS Breakdown — L2BEAT","type":"research","url":"https://l2beat.com/scaling/projects/taiko/tvs-breakdown"},{"credibility":1,"name":"Taiko Raises US$37M from Top-tier VCs — PRNewswire","type":"news_article","url":"https://www.prnewswire.com/news-releases/taiko-raises-us37m-from-top-tier-vcs-ahead-of-mainnet-launch-302077780.html"},{"credibility":2,"name":"Ethereum Layer 2 Taiko goes live on mainnet — The Block","type":"news_article","url":"https://www.theblock.co/post/296831/ethereum-l2-taiko-mainnet"},{"credibility":2,"name":"Ethereum Layer 2 Taiko announces genesis airdrop ahead of mainnet — The Block","type":"news_article","url":"https://www.theblock.co/post/296168/ethereum-layer-2-taiko-announces-genesis-airdrop-ahead-of-mainnet"},{"credibility":2,"name":"Daniel Wang — Co-Founder & CEO @ Taiko Labs — Crunchbase","type":"other","url":"https://www.crunchbase.com/person/daniel-wang-4"},{"credibility":2,"name":"Ethereum L2 Bridge Exploit Drains $1.7M — TechTimes","type":"news_article","url":"https://www.techtimes.com/articles/318886/20260623/ethereum-l2-bridge-exploit-drains-17m-leaked-sgx-key-defeats-taiko-trust-model.htm"},{"credibility":2,"name":"Succinct's SP1 bug sparks transparency debate in ZK security — Blockworks","type":"news_article","url":"https://blockworks.co/news/succinct-sp1-bug"},{"credibility":1,"name":"Taiko Bridge: Etherscan Contract Address","type":"on_chain","url":"https://etherscan.io/address/0xd60247c6848b7ca29eddf63aa924e53db6ddd8ec"},{"credibility":2,"name":"Taiko Hack Forces Bridge Withdrawal Warning — Bitcoin Foundation","type":"news_article","url":"https://bitcoinfoundation.org/news/blockchain-news/ethereum-l2-taiko-hack-forces-bridge-warning-amid-1-7m-exploit/"},{"credibility":2,"name":"Taiko urges users to exit bridges after a verification flaw — MEXC News","type":"news_article","url":"https://www.mexc.com/news/1163847"},{"credibility":3,"name":"Taiko Bridge Exploit June 2026 — SpotedCrypto","type":"news_article","url":"https://www.spotedcrypto.com/taiko-bridge-exploit-june-2026/"},{"credibility":2,"name":"Taiko urges immediate withdrawal after chain verification breach — Crypto Briefing","type":"news_article","url":"https://cryptobriefing.com/taiko-exploited-2m-tko-mexc/"},{"credibility":2,"name":"Taiko price today, TAIKO to USD — CoinMarketCap","type":"other","url":"https://coinmarketcap.com/currencies/taiko/"},{"credibility":2,"name":"Introducing Raiko, Taiko's multi-prover — Taiko Mirror","type":"official","url":"https://taiko.mirror.xyz/qmw6Or2T8OnadFpqULXDZaIzsBKRVvavB-AEUvp6fxM"}],"summary":"Taiko (ticker: TAIKO) is an Ethereum-equivalent, based contestable ZK-rollup Layer 2 developed by Taiko Labs, founded in 2022 by Daniel Wang, former founder of Loopring. The protocol launched on Ethereum mainnet on May 27, 2024 and raised $37 million in total funding. On June 22, 2026, an attacker exploited a critical operational security failure — an SGX RSA-3072 private signing key committed to a public GitHub repository — to forge valid L2 state attestations and drain approximately $1.7 million from the L1 Bridge and ERC20Vault contracts; Taiko halted block production, paused all bridge withdrawals, and pledged full treasury-backed reimbursement to affected users.","timeline":[{"date":"2022-03-01","event":"Taiko Labs founded by Daniel Wang, former CEO and founder of Loopring.","source":"Crunchbase / Gate.com","source_url":"https://www.crunchbase.com/person/daniel-wang-4"},{"date":"2024-03-02","event":"Taiko Labs closes $15 million Series A led by Lightspeed Faction, bringing total funding to $37 million.","source":"PRNewswire","source_url":"https://www.prnewswire.com/news-releases/taiko-raises-us37m-from-top-tier-vcs-ahead-of-mainnet-launch-302077780.html"},{"date":"2024-05-22","event":"Taiko announces genesis airdrop of up to 5% of TAIKO token supply (50 million tokens) to over 300,000 community members.","source":"The Block","source_url":"https://www.theblock.co/post/296168/ethereum-layer-2-taiko-announces-genesis-airdrop-ahead-of-mainnet"},{"date":"2024-05-27","event":"Taiko launches on Ethereum mainnet as the first based rollup, with Vitalik Buterin submitting the inaugural block.","source":"The Block","source_url":"https://www.theblock.co/post/296831/ethereum-l2-taiko-mainnet"},{"date":"2024-06-05","event":"TAIKO token generation event (TGE); token begins trading.","source":"CoinMarketCap","source_url":"https://coinmarketcap.com/currencies/taiko/"},{"date":"2025-01-01","event":"A critical vulnerability in Plonky3 (a dependency of SP1, one of Taiko's ZK prover backends) is publicly disclosed; patched by Succinct in SP1 v4 (Turbo). Taiko's multi-proof architecture was credited with limiting the impact.","source":"Blockworks","source_url":"https://blockworks.co/news/succinct-sp1-bug"},{"date":"2026-06-22","event":"Exploit occurs: attacker uses publicly exposed SGX RSA-3072 signing key (enclave-key.pem in taikoxyz/raiko GitHub repository) to forge valid L2 state attestations, drain the L1 Bridge and ERC20Vault of approximately $1.7 million, and move ~1.99 million TAIKO tokens to MEXC.","source":"The Defiant / CoinDesk / Crypto Times","source_url":"https://thedefiant.io/news/hacks/taiko-bridge-exploit-sgx-signing-key-github-1-7m"},{"date":"2026-06-22","event":"Taiko halts block production, pauses L1 Bridge and ERC20Vault withdrawals via Security Council 7-of-9 multisig, requests exchanges freeze TAIKO deposits, and publishes attacker wallet addresses. TAIKO token drops over 10%.","source":"CoinDesk","source_url":"https://www.coindesk.com/tech/2026/06/22/taiko-halts-its-ethereum-layer-2-network-after-a-bridge-exploit-token-dives-10"},{"date":"2026-06-22","event":"Four pull requests labeled respond-to-hack merged into Taiko's codebase within 24 hours; PR #21820 addresses signing infrastructure changes.","source":"Thirdweb Blog","source_url":"https://blog.thirdweb.com/taiko-bridge-exploit-explained-how-a-leaked-key-led-to-1-7m-in-forged-withdrawals/"},{"date":"2026-06-25","event":"Taiko publishes update confirming no user funds will be lost, pledging to fully recollateralize the bridge 1:1 before reopening. CEO files formal report with Singapore authorities. No specific reopening date announced.","source":"Crypto Times","source_url":"https://www.cryptotimes.io/2026/06/25/taiko-to-fully-restore-bridge-backing-after-1-7m-hack/"}]},"v":1}