> 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/security-overview/introduction.md).

# Introduction

Security is the paramount value that every Cypherock wallet is built upon. Here is how Cypherock X1 and Cypherock X0 each put it into practice.

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{% tab title="Cypherock X1" %}
Security is the paramount value which Cypherock X1 was built upon. Cypherock X1 offers state-of-the-art security features that make it the ideal wallet to HODL your Crypto with peace of mind.

1. **Open-Source with Secure Elements:** Traditionally wallets had to make a choice between becoming open-source or using closed-sourced secure elements bounded by NDAs. Cypherock have the best of both Worlds. X1 Vault is open source and stores 1 of the 5 shards and the 4 X1 Cards have EAL 6+ secure elements and store the remaining 4 of the 5 shards.
2. **Distributed Entropy Generation:** Entropy in X1 Vault is generated through XOR between the random number generated by the STM32L4 chip and the ATECC chip to avoid any single point of failure in entropy generation. The user can also input their own seed phrase if they want.
3. **Server-based Security Validation:** Both X1 Vault and X1 Cards are required to be authenticated successfully through the server before the product can be used by the user. This ensures protection against supply chain attacks.
4. **Distributed Key Storage:** The master key unlike other wallets is never stored in a single place permanently in Cypherock X1. The private key for a specific coin is generated in real-time in the RAM from the X1 Vault and any X1 Card, the transaction is signed, and then the private key is deleted from the RAM then itself. It never touches permanent storage ever.
5. **PIN Protection over Key Material:** Each of the shards stored on the X1 Vault and the 4 X1 Cards is also protected by a user-generated alphanumeric PIN that has brute force protection enforced by secure elements.
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{% tab title="Cypherock X0" %}
Security is the paramount value which Cypherock X0 was built upon, just like Cypherock X1. Cypherock X0 brings the same security standard to a mobile-first experience.

1. **Secure Computation inside the X0 Card:** Every operation on key material, from wallet reconstruction and key derivation to transaction signing, happens inside the EAL6+ certified secure element of the X0 Card. The smartphone never reconstructs the wallet, derives keys or signs.
2. **Server-based Security Validation:** All 4 X0 Cards are required to be authenticated successfully through Cypherock's server during setup before the product can be used by the user. This ensures protection against supply chain attacks.
3. **Distributed Key Storage:** The master key is never stored in a single place permanently in Cypherock X0. It is split into 5 shards stored on the 4 X0 Cards and the user's smartphone. The private key for a specific coin is generated inside the X0 Card from its own shard and the smartphone's shard, the transaction is signed, and then the private key is erased from the card's memory immediately.
4. **PIN Protection over Key Material:** Every wallet on Cypherock X0 is protected by a mandatory alphanumeric PIN. The PIN is verified only inside the X0 Card, a key derived from it encrypts every shard, and brute force attempts are prevented by CyLock.
5. **Hardware-backed Storage on the Smartphone:** The smartphone's shard is encrypted with a key derived from the wallet PIN and stored in the smartphone's hardware-backed secure storage, the Keychain on iOS and the Keystore on Android.
   {% endtab %}
   {% endtabs %}