> For the complete documentation index, see [llms.txt](https://solident.gitbook.io/solident-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://solident.gitbook.io/solident-docs/appendix/glossary-technical-terms.md).

# Glossary of technical terms

#### AES-256 (Advanced Encryption Standard, 256-bit)

A symmetric encryption algorithm widely regarded as the gold standard for data security.

* In Solident: Used to encrypt biometric templates and pattern hashes stored locally and in backup.
* Provides resistance against brute-force attacks even with future computing advances.
* Reference: [NIST AES Specification](https://csrc.nist.gov/publications/detail/fips/197/final)

***

#### SHA-3 (Secure Hash Algorithm 3)

A cryptographic hash function that transforms data into fixed-length outputs, impossible to reverse.

* In Solident: Used to hash pattern lock inputs with added salt before encryption.
* Ensures that even if the hash is exposed, the original pattern cannot be reconstructed.
* Reference: [NIST SHA-3 Standard](https://csrc.nist.gov/publications/detail/fips/202/final)

***

#### Ed25519

A public-key signature system based on elliptic-curve cryptography.

* In Solident: Generates wallet keys and signs Solana transactions.
* Combines speed, efficiency, and strong security, making it the Solana ecosystem’s default standard.
* Reference: [RFC 8032: Edwards-Curve Digital Signature Algorithm (EdDSA)](https://www.rfc-editor.org/rfc/rfc8032)

***

#### TLS 1.3 (Transport Layer Security)

The latest protocol for securing communication over the internet.

* In Solident: Encrypts all communication with RPC providers like Helius.
* Provides forward secrecy: past sessions remain safe even if current keys are compromised.
* Reference: [RFC 8446: The Transport Layer Security (TLS) Protocol Version 1.3](https://www.rfc-editor.org/rfc/rfc8446)

***

#### Secure Enclave / TEE (Trusted Execution Environment)

A dedicated, isolated hardware environment inside devices where sensitive operations occur.

* In Solident: Stores encryption keys, verifies biometrics, and signs transactions.
* Prevents the operating system or apps from accessing raw biometric or key material.
* Reference: [ARM TrustZone Overview](https://developer.arm.com/architectures/security-architectures/trustzone)

***

#### Helius RPC

A specialized RPC (Remote Procedure Call) service provider for Solana.

* In Solident: Handles transaction broadcasting, balance queries, and real-time updates.
* Provides higher speed and reliability compared to default RPC nodes.
* Reference: [Helius Official Docs](https://docs.helius.dev/)

***

#### Session Token

A short-lived cryptographic credential generated after successful biometric + pattern authentication.

* In Solident: Used instead of seed phrases to log into dApps.
* Automatically expires to reduce hijacking risks and is unique per session/device.
* Reference: [OAuth 2.0 Token Concepts (IETF)](https://www.rfc-editor.org/rfc/rfc6749)

***

#### Pattern Lock (3x3 Grid)

A visual secondary authentication method where users connect at least four points on a 3x3 grid.

* In Solident: Works alongside face recognition as a two-factor model.
* The input is hashed and encrypted, never stored as plain text.
* Reference: [Android Pattern Lock Research (USENIX Security)](https://www.usenix.org/conference/soups2017/technical-sessions/presentation/aviv)

***

#### Zero-Knowledge Proof (ZKP)

A cryptographic method that lets one party prove something is true without revealing the data itself.

* In Solident: Planned for Phase 4 — biometric hash proofs may be anchored on-chain with ZKPs.
* Allows public integrity checks of biometric backups without exposing sensitive templates.
* Reference: [Zero-Knowledge Proofs Explained (Stanford Applied Crypto Group)](https://crypto.stanford.edu/pbc/notes/crypto/zk.html)