{"document_id":"BLC-STUDY-0653","slug":"iron-fish","title":"Iron Fish: a shielded payments chain","authors":"Iron Fish","year":2021,"date_label":"2021","publisher":"Iron Fish","paper_type":"Design paper","category":"Privacy","topics":["Privacy"],"source_url":"https://ironfish.network/learn/whitepaper","source_label":"Iron Fish whitepaper","legacy_pdf_path":null,"sha256":null,"sha256_note":"No hash is published. This build does not store those PDF bytes, so a checksum would be invented. Where a legacy path exists, it points at the Internet Archive copy of the old library.","version":"Source cited by the 2021 study. The study is the reading. This page does not add a second essay.","doi":null,"rights_status":"Official external source only","source_status":"Official source","use_status":"Metadata and commentary only. The reading is the study page.","licence":null,"licence_label":"No licence recorded. Rights status under review.","full_text":null,"full_text_reason":"Full text is not published on this page. Public availability is not a licence to republish a document. Blockchain Lab has not recorded a licence that permits an HTML transcription, a training set, or a retrieval corpus of the paper. Text on this page is Blockchain Lab's own wording, or a pointer to a study that is also Blockchain Lab's wording.","repository":null,"editorial_line":"Iron Fish publishes a payments chain whose transfers are shielded by default, using a note and nullifier construction in the Sapling line.","canonical_url":"https://blockchainlab.com/whitepaper/iron-fish","record_url":"https://blockchainlab.com/research/corpus/papers/iron-fish","study_url":"https://blockchainlab.com/whitepaper/iron-fish","last_reviewed":"2026-10-01","last_checked":"2026-10-01","relationships":[{"rel":"Canonical reading","label":"Iron Fish study","href":"/whitepaper/iron-fish"},{"rel":"Related paper","label":"Zerocash","href":"/whitepaper/zerocash"},{"rel":"Related paper","label":"Penumbra","href":"/whitepaper/penumbra-protocol"},{"rel":"Related paper","label":"Namada","href":"/whitepaper/namada-shielded"}]}