Open Source
The parts of Cryptograph that handle your keys are open source: key storage, cryptographic primitives, transaction signing, and transaction decoding.
The watch UI, product logic, and user experience remain closed source for now.
We maintain forks of key cryptographic libraries optimized for watchOS, and contribute new tools back to the ecosystem.
New Contribution
A minimal, no_std Rust library for Zcash transaction signing. As far as we know, this is the first production implementation of Orchard PCZT signing — enabling shielded Zcash transactions on resource-constrained devices like Apple Watch.
The library implements ZIP-32 key derivation, RedPallas (Orchard) and RedJubjub (Sapling) signature schemes, with no heap allocation required. We built this because no existing library could run within watchOS constraints.
| Repository | Purpose |
|---|---|
| wallet-core |
Fork of Trust Wallet's WalletCore with watchOS support. Handles BIP-39 mnemonic generation, BIP-32 key derivation, and transaction signing for Bitcoin, Ethereum, Base, and Solana. Our fork integrates directly with the Secure Enclave and adds explicit buffer zeroing to ensure sensitive key material is wiped from memory after use.
perpetua-engineering/wallet-core → |
| zcash-swift-wallet-sdk |
Fork of the official Zcash iOS SDK, modified to work with our PCZT signing flow where keys remain on the watch.
perpetua-engineering/zcash-swift-wallet-sdk → |
| zcash-light-client-ffi |
Swift bindings for the Zcash light client, enabling blockchain sync and transaction building on iOS.
perpetua-engineering/zcash-light-client-ffi → |
| pczt |
Partially Created Zcash Transaction format implementation. Enables splitting transaction creation (phone) from signing (watch).
perpetua-engineering/pczt → |
| zcash-transparent |
New library extracting transparent signing primitives from librustzcash. Built to run within watchOS constraints where the full librustzcash cannot.
perpetua-engineering/zcash-transparent → |
| orchard |
Fork of the Orchard shielded protocol implementation with modifications for our signing flow.
perpetua-engineering/orchard → |
| sapling-crypto |
Fork of Sapling cryptographic primitives for legacy shielded address support.
perpetua-engineering/sapling-crypto → |
Every cryptographic primitive, every networking library, every build tool we use was crafted by someone who believed in sharing knowledge freely.
From the mathematicians who designed elliptic curves to the developers who implemented them in battle-tested libraries — your work protects real people and real assets.
We commit to giving back. Our own contributions are available on GitHub, and we actively support the projects we depend on.
To every contributor, maintainer, and reviewer: thank you.