> For the complete documentation index, see [llms.txt](https://learn.cypherock.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://learn.cypherock.com/design-decision.md).

# DESIGN DECISION

- [The balance between security and convenience](https://learn.cypherock.com/design-decision/the-balance-between-security-and-convenience.md)
- [Cypherock X0 Hardware Architecture](https://learn.cypherock.com/design-decision/cypherock-x0-hardware-architecture.md)
- [Encrypted NFC communication for X0 cards](https://learn.cypherock.com/design-decision/cypherock-x0-hardware-architecture/encrypted-nfc-communication-for-x0-cards.md)
- [Why the X0 card signs your transactions](https://learn.cypherock.com/design-decision/cypherock-x0-hardware-architecture/why-the-x0-card-signs-your-transactions.md)
- [Why the X0 cards are not upgradeable](https://learn.cypherock.com/design-decision/cypherock-x0-hardware-architecture/why-the-x0-cards-are-not-upgradeable.md)
- [How the X0 wallet app protects its shard](https://learn.cypherock.com/design-decision/cypherock-x0-hardware-architecture/how-the-x0-wallet-app-protects-its-shard.md)
- [Cypherock X1 Hardware Architecture](https://learn.cypherock.com/design-decision/cypherock-x1-hardware-architecture.md)
- [Using ultrasonic welding for the x1 vault enclosure](https://learn.cypherock.com/design-decision/cypherock-x1-hardware-architecture/using-ultrasonic-welding-for-the-x1-vault-enclosure.md)
- [Encrypted nfc communication for x1 cards](https://learn.cypherock.com/design-decision/cypherock-x1-hardware-architecture/encrypted-nfc-communication-for-x1-cards.md)
- [Using javacards instead of microsd](https://learn.cypherock.com/design-decision/cypherock-x1-hardware-architecture/using-javacards-instead-of-microsd.md)
- [Choosing USB vs QR code](https://learn.cypherock.com/design-decision/cypherock-x1-hardware-architecture/choosing-usb-vs-qr-code.md)
- [Why the X1 cards are not upgradeable](https://learn.cypherock.com/design-decision/cypherock-x1-hardware-architecture/why-the-x1-cards-are-not-upgradeable.md)
- [Cypherock is BIP39 compliant](https://learn.cypherock.com/design-decision/cypherock-is-bip39-compliant.md)
- [Private keys should be near to impossible to extract](https://learn.cypherock.com/design-decision/private-keys-should-be-near-to-impossible-to-extract.md)
- [Conflict between trusted parties should not result in unauthorized access](https://learn.cypherock.com/design-decision/conflict-between-trusted-parties-should-not-result-in-unauthorized-access.md)
- [Using Shamir Secret Sharing vs. Multi-sig](https://learn.cypherock.com/design-decision/using-shamir-secret-sharing-vs.-multi-sig.md)
- [How is Shamir Secret Sharing implemented within Cypherock X0](https://learn.cypherock.com/design-decision/using-shamir-secret-sharing-vs.-multi-sig/how-is-shamir-secret-sharing-implemented-within-cypherock-x0.md)
- [How is Shamir Secret Sharing implemented within Cypherock X1](https://learn.cypherock.com/design-decision/using-shamir-secret-sharing-vs.-multi-sig/how-is-shamir-secret-sharing-implemented-within-cypherock-x1.md)
- [Why Cypherock has a default 2/5 threshold scheme](https://learn.cypherock.com/design-decision/using-shamir-secret-sharing-vs.-multi-sig/why-cypherock-has-a-default-2-5-threshold-scheme.md)
- [Rejected Key Schemes](https://learn.cypherock.com/design-decision/using-shamir-secret-sharing-vs.-multi-sig/rejected-key-schemes.md)
- [Pin Protection on Cypherock X0](https://learn.cypherock.com/design-decision/pin-protection-on-cypherock-x0.md)
- [Pin Protection on Cypherock X1](https://learn.cypherock.com/design-decision/pin-protection-on-cypherock-x1.md)
- [Difference between backing up your Pin vs. Seed Phrase](https://learn.cypherock.com/design-decision/pin-protection-on-cypherock-x1/difference-between-backing-up-your-pin-vs.-seed-phrase.md)