# Tether (USDT) Quantum Readiness Report

> Tether has a QRI score of 3/100 and is assessed at Stage 1 (Quantum Risk Assessed) with high evidence confidence.

Evaluation date: 2026-06-01. Review status: draft. Evaluated scope: Multi-chain fiat-backed stablecoin token; token-specific admin/governance keys evaluated separately per QRI Token Inheritance rule (Section 7.2). Host-chain quantum posture evaluated separately..

Tether (USDT) is a multi-chain fiat-backed stablecoin token with no native blockchain or custom cryptographic primitives. User-level transfer security inherits host-chain quantum posture (evaluated separately). This evaluation focuses on token-specific admin/governance keys per QRI Token Inheritance rule (Section 7.2). USDT admin keys (mint, burn, freeze, destroyBlackFunds) on all host chains are controlled by ECDSA-based addresses with permanently exposed public keys. On Ethereum, a 3-of-6 Gnosis Safe multisig (0xC6CDE7C39eB2f0F0095F41570af89eFC2C1Ea828) holds all admin authority; all six signer EOAs have transacted on-chain, permanently exposing their ECDSA public keys. Similar exposure exists on TRON, Solana, and all other host chains. The Google Quantum AI whitepaper (March 30, 2026) explicitly identifies USDT admin keys among approximately 70 high-value Ethereum contracts with exposed keys, estimating compromise in minutes on a fast-clock CRQC with fewer than 500,000 physical qubits. A quantum attacker compromising any major-chain admin key could mint unlimited unbacked tokens, collapsing the fiat peg across the entire approximately $200B ecosystem. Tether has published no quantum risk assessment, cryptographic inventory, PQ migration roadmap, or testnet. The CEO acknowledged the threat in February 2025 but characterized it as distant. As of 2026-06-01, no production PQC or hybrid-PQ protection exists anywhere in the USDT admin infrastructure. By contrast, Circle (USDC) published a comprehensive post-quantum security whitepaper and roadmap in May 2026. QRI Score: 3/100. Stage 1 (Quantum Risk Assessed). The score reflects zero quantum protection across all evaluated categories except that USDT contract code is publicly verifiable on-chain.

## Core resources

- [Tether QRI report](https://qrindex.org/projects/tether/): Human-readable assessment with score, stage, evidence, blockers, risks, and assurance notes.
- [Tether structured report data](https://qrindex.org/projects/tether/report.json): Complete report as JSON for deterministic machine processing.
- [QRI methodology](https://qrindex.org/methodology/): Scoring model, evidence handling, readiness stages, confidence, assurance, and report status.
- [All QRI project reports](https://qrindex.org/llms.txt): Score-ranked index of every published project assessment.
- [Tether official website](https://tether.to): Project-maintained website.
- [Tether source repository 1](https://github.com/tetherto): Project source code referenced by QRI.



## Evidence sources

- [Evidence source 1](<https://tether.to/en/supported-protocols/>): Public source cited by the Tether QRI assessment.
- [Evidence source 2](<https://tether.to/transparency/>): Public source cited by the Tether QRI assessment.
- [Evidence source 3](<https://tether.to/public/Relevant_Information_Document_-_Tether_International,_S.A._de_C.V..pdf>): Public source cited by the Tether QRI assessment.
- [Evidence source 4](<https://github.com/tetherto>): Public source cited by the Tether QRI assessment.
- [Evidence source 5](<https://etherscan.io/address/0xdAC17F958D2ee523a2206206994597C13D831ec7#code>): Public source cited by the Tether QRI assessment.
- [Evidence source 6](<https://etherscan.io/address/0xc6cde7c39eb2f0f0095f41570af89efc2c1ea828>): Public source cited by the Tether QRI assessment.
- [Evidence source 7](<https://stablepqc.com/>): Public source cited by the Tether QRI assessment.
- [Evidence source 8](<https://explorer.bitquery.io/tron/trc20token/TR7NHqjeKQxGTCi8q8ZY4pL8otSzgjLj6t/smart_contract>): Public source cited by the Tether QRI assessment.
- [Evidence source 9](<https://usdt.network/blockchains>): Public source cited by the Tether QRI assessment.
- [Evidence source 10](<https://tether.to/>): Public source cited by the Tether QRI assessment.
- [Evidence source 11](<https://tether.io/news/>): Public source cited by the Tether QRI assessment.
- [Evidence source 12](<https://etherscan.io/address/0xc6cde7c39eb2f0f0095f41570af89efc2c1ea828#code>): Public source cited by the Tether QRI assessment.