1# HUKS<a name="EN-US_TOPIC_0000001148528849"></a> 2 3- [Introduction](#section11660541593) 4- [Directory Structure](#section161941989596) 5- [Repositories Involved](#section1371113476307) 6 7## Introduction<a name="section11660541593"></a> 8 9OpenHarmony Universal KeyStore \(HUKS\) provides applications with key library capabilities, such as key management and cryptographic operations on keys. HUKS also provides APIs for applications to import or generate keys. 10 11HUKS consists of the following modules: 12 13- HUKS SDK layer: provides HUKS APIs for applications. 14 15- HUKS service layer: implements functions such as HUKS key management and storage. 16- HUKS engine layer: HUKS core module, which generates, encrypts, and decrypts keys. For devices running a standard system, this module of the commercial version must run in a secure environment such as a TEE or a chip with security capabilities. A secure environment requires dedicated hardware and is therefore implemented only by emulation in the open-source code. For the small and mini systems, HUKS only provides the example implementation of the root key protection solution. In commercial scenarios, the implementation must adapt to the protection solution for either the hardware root key or other root keys. 17 18## Directory Structure<a name="section161941989596"></a> 19 20``` 21base/security/huks/ 22├── build # Build configuration file 23├── frameworks # Framework code, which is used by interfaces and services 24│ └── huks_standard # Code implementation 25| └── huks_lite # Build script in a small and mini systems 26| └── crypto_lite # Encryption and decryption implementation 27├── interfaces # APIs 28│ └── innerkits 29│ └── kits 30├── services 31│ └── huks_standard 32├── test 33└── utils 34 └── crypto_adapter 35 └── file_operator 36 └── list 37 └── mutex 38``` 39 40## Repositories Involved<a name="section1371113476307"></a> 41 42**Security subsystem** 43 44**[security_huks](https://gitee.com/openharmony/security_huks)**