Does INTCx / USDC match its issuer's published contract?

QED signs a canonical JSON payload. Fetch the public key from /.well-known/qed.json, then check the signature against this payload.

Canonical JSON

{"block":26251666,"chain":"ethereum","checked_at":"2026-10-23T00:13:26Z","dev":false,"expires_at":"2026-10-24T00:13:26Z","issuer":"Backed xStocks","pool":{"base":{"address":"0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48","balance":"103649470","decimals":6,"symbol":"USDC"},"chain":"ethereum","dex":"uniswap-v4","pool":"0x9995c15cb4b035510ae8474e0b4e56959310c17ce331ede773860b85a279d4d6","quote":{"address":"0xf8A80D1cb9cFD70D03D655D9dF42339846F3B3C8","balance":"949459057325626081","decimals":18,"symbol":"INTCx"}},"quote_share_of_supply":3.390925204734379e-6,"reads":[{"block":null,"method":"eth_call","params":["0xbd216513d74c8cf14cf4747e6aaa6420ff64ee9e","poolKeys","0x9995c15cb4b035510ae8474e0b4e56959310c17ce331ede773"],"raw_result":"Object {\"currency0\": String(\"0xa0b86991c6218b36c1d19d4a2e9eb0ce3606eb48\"), \"currency1\": String(\"0xf8a80d1cb9cfd70d03d655d9df42339846f3b3c8\"), \"fee\": String(\"880000\"), \"hooks\": String(\"0x0000000000000000000000000000000000000000\"), \"tickSpacing\": String(\"17600\")}","result_hash":"9a8c9e6ea6514f23a580f3136cc77c5eac6b01bfe3c2e732bff3e7a228d25b1a","slot":null},{"block":null,"method":"eth_call","params":["0x7ffe42c4a5deea5b0fec41c94c136cf115597227","getSlot0","0x9995c15cb4b035510ae8474e0b4e56959310c17ce331ede773860b85a279d4d6"],"raw_result":"true","result_hash":"18d10c7d2b4b04aaf04254d1ae5d655a5dc0407cbcdd5a8c3986e985370f36ee","slot":null},{"block":null,"method":"eth_call","params":["0x7ffe42c4a5deea5b0fec41c94c136cf115597227","getLiquidity","0x9995c15cb4b035510ae8474e0b4e56959310c17ce331ede773860b85a279d4d6"],"raw_result":"9920228262781","result_hash":"38d1bc9b27e02575b59ac1f546592f0d86a80d7e3ce6e3f3a8517d5f741e906c","slot":null},{"block":null,"method":"eth_call","params":["0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48","symbol()"],"raw_result":"Some(\"USDC\")","result_hash":"a3c9e246b0832b52e41efce041d8614251f5e288cdd4b192e85bfd3dfcb748ff","slot":null},{"block":null,"method":"eth_call","params":["0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48","decimals()"],"raw_result":"Some(6)","result_hash":"c68fe6989b1835302197d0af5be845dfab10ed9f9632205eb4ab5b949b9e1a6a","slot":null},{"block":null,"method":"eth_call","params":["0xf8A80D1cb9cFD70D03D655D9dF42339846F3B3C8","symbol()"],"raw_result":"Some(\"INTCx\")","result_hash":"e9467b15f2d5453edcaff219c77833111c55d28936b5d3787354751a8f5b7f0c","slot":null},{"block":null,"method":"eth_call","params":["0xf8A80D1cb9cFD70D03D655D9dF42339846F3B3C8","decimals()"],"raw_result":"Some(18)","result_hash":"c14f173ff30df32f36fac2ea29d9a20482082428fd32b58be5433d310884f764","slot":null},{"block":26251666,"method":"eth_blockNumber","params":[],"result_hash":"430752224241db629e93cd7cc8d367fbcf4b3de9a2b6a304702723f8d05e5f9f","slot":null},{"block":null,"method":"eth_call","params":["0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48","symbol()"],"raw_result":"Some(\"USDC\")","result_hash":"a3c9e246b0832b52e41efce041d8614251f5e288cdd4b192e85bfd3dfcb748ff","slot":null},{"block":null,"method":"eth_call","params":["0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48","name()"],"raw_result":"Some(\"USD Coin\")","result_hash":"fe94af15dc887a2c9df1fb0d6d276e6c586ca9d430ffeac0d05e4baee0637fd1","slot":null},{"block":null,"method":"eth_call","params":["0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48","decimals()"],"raw_result":"Some(6)","result_hash":"c68fe6989b1835302197d0af5be845dfab10ed9f9632205eb4ab5b949b9e1a6a","slot":null},{"block":null,"method":"eth_call","params":["0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48","totalSupply()"],"raw_result":"Some(\"48116102217330294\")","result_hash":"161969e6f84e2daf7c4f155514c47786246a77dc28faa7cff3183437686f701c","slot":null},{"block":null,"method":"eth_call","params":["0xf8A80D1cb9cFD70D03D655D9dF42339846F3B3C8","symbol()"],"raw_result":"Some(\"INTCx\")","result_hash":"e9467b15f2d5453edcaff219c77833111c55d28936b5d3787354751a8f5b7f0c","slot":null},{"block":null,"method":"eth_call","params":["0xf8A80D1cb9cFD70D03D655D9dF42339846F3B3C8","name()"],"raw_result":"Some(\"Intel xStock\")","result_hash":"db7d1ef6a57d9365889cd038febbf45e50b19e999fbdf0413bdcf8f8e285ae0c","slot":null},{"block":null,"method":"eth_call","params":["0xf8A80D1cb9cFD70D03D655D9dF42339846F3B3C8","decimals()"],"raw_result":"Some(18)","result_hash":"c14f173ff30df32f36fac2ea29d9a20482082428fd32b58be5433d310884f764","slot":null},{"block":null,"method":"eth_call","params":["0xf8A80D1cb9cFD70D03D655D9dF42339846F3B3C8","totalSupply()"],"raw_result":"Some(\"280000000000000000000000\")","result_hash":"78aaa4c1716265efe0c017a719825aa8ecf1516516b90d2b6c13c7105393aef1","slot":null},{"block":null,"method":"eth_getCode","params":["0xf8A80D1cb9cFD70D03D655D9dF42339846F3B3C8","latest"],"result_hash":"71ee049d0c0cab5d785d7aef2e6b591e511475fb8ef465f4d8f5335bfd412bfd","slot":null},{"block":null,"method":"eth_getCode","params":["0xf8A80D1cb9cFD70D03D655D9dF42339846F3B3C8","latest"],"result_hash":"71ee049d0c0cab5d785d7aef2e6b591e511475fb8ef465f4d8f5335bfd412bfd","slot":null}],"registry_entry":{"chain":"ethereum","contract":"0xf8A80D1cb9cFD70D03D655D9dF42339846F3B3C8","decimals":null,"issuer":"Backed xStocks","last_checked":"2026-10-23T00:11:43Z","name":"Intel","official_deployments":[{"address":"0xf8a80d1cb9cfd70d03d655d9df42339846f3b3c8","network":"Ethereum","wrapper_address":"0x6a2a68ca7fc793d8cea36326a6ec1ef7ac3d9742","wrapper_address_v2":"0x33aa35b0271fffe2048cc093ab7fe60931786719"},{"address":"0xf8a80d1cb9cfd70d03d655d9df42339846f3b3c8","network":"BinanceSmartChain","wrapper_address":"0x6a2a68ca7fc793d8cea36326a6ec1ef7ac3d9742","wrapper_address_v2":"0x33aa35b0271fffe2048cc093ab7fe60931786719"},{"address":"0xf8a80d1cb9cfd70d03d655d9df42339846f3b3c8","network":"Arbitrum","wrapper_address":"0x6a2a68ca7fc793d8cea36326a6ec1ef7ac3d9742","wrapper_address_v2":"0x33aa35b0271fffe2048cc093ab7fe60931786719"},{"address":"XshPgPdXFRWB8tP1j82rebb2Q9rPgGX37RuqzohmArM","network":"Solana"},{"address":"TMkWtCUBF9zatuda6onxoPeAUvkGiwaCHP","network":"Tron"},{"address":"EQBBnSFyNZkNmq7I4E9yWhZDZQurcQhGkFeGBV_UXibFlv4-","network":"Ton"},{"address":"0xf8a80d1cb9cfd70d03d655d9df42339846f3b3c8","network":"Mantle","wrapper_address":"0x6a2a68ca7fc793d8cea36326a6ec1ef7ac3d9742","wrapper_address_v2":"0x33aa35b0271fffe2048cc093ab7fe60931786719"},{"address":"0xf8a80d1cb9cfd70d03d655d9df42339846f3b3c8","network":"HyperEVM","wrapper_address_v2":"0x33aa35b0271fffe2048cc093ab7fe60931786719"},{"address":"0xf8a80d1cb9cfd70d03d655d9df42339846f3b3c8","network":"Ink","wrapper_address_v2":"0x33aa35b0271fffe2048cc093ab7fe60931786719"},{"address":"0xf8a80d1cb9cfd70d03d655d9df42339846f3b3c8","network":"XLayer","wrapper_address_v2":"0x33aa35b0271fffe2048cc093ab7fe60931786719"},{"address":"0xf8a80d1cb9cfd70d03d655d9df42339846f3b3c8","network":"Optimism","wrapper_address_v2":"0x33aa35b0271fffe2048cc093ab7fe60931786719"},{"address":"0xf8a80d1cb9cfd70d03d655d9df42339846f3b3c8","network":"Monad","wrapper_address_v2":"0x33aa35b0271fffe2048cc093ab7fe60931786719"}],"source":"xstocks-api","source_url":"https://api.xstocks.fi/api/v2/public/assets","ticker":"INTC"},"registry_hash":"9067df56b065ce18a8c928496dee402e28e9c225326d10e644749ce72c5af057","signer":"GJWKkiUd3zj1pJGfeE7JitiPiwDJC6XmNFvpJWJuvvpn","slot":null,"subject":"0x9995c15cb4b035510ae8474e0b4e56959310c17ce331ede773860b85a279d4d6","ticker":"INTC","verdict":{"Verified":{"issuer":"Backed xStocks","ticker":"INTC"}},"version":1}

Signature

qyPGH/XFTJFCOGkWNI3rjQjqUMgHzyJeJ1Lvgo/iOnAwE5XYmNu/nMFz3IGwn2Fuvd+gGMRAqAiAqywi9BDWDw==

API call

GET /api/attest/194520d958bee1d42cd0441b1341161d80ad5441799f15e8f703c987fe401d36

1. Fetch the public key and attestation JSON, then verify the signature with the published key.
2. Canonicalize the payload with sorted object keys and no whitespace, then verify its SHA-256 attestation id.
3. Run the API call above and compare the returned payload, serial, signer, and signature with this certificate.