add SIG meeting info of MA

sigs/security/README.md

 # MindSpore Security Special Interest Group (SIG)
 
-This is the working repo for the MindArmour special interest group (SIG). This repo contains all the artifacts, materials, meeting notes and proposals regarding **model security** and **Data privacy protection** in MindSpore. Feedbacks and contributions are welcome.
+This is the working repo for the MindArmour special interest group (SIG). This repo contains all the artifacts, materials, meeting notes and proposals regarding **model security**, **Data privacy protection** and **AI Fuzzer** in MindSpore. Feedbacks and contributions are welcome.
 1. **model security**: The model security contains four features: attack, detect, defense and evaluate.
-2. **Data privacy protection**: We will implemented this feature very soon.
+2. **Data privacy protection**: Use differential privacy to protect model's information.
+3. **AI Fuzzer**: Coverage-gain based fuzzer to evalution the robustness of given model.
 
 # SIG Leads
 
-* Zheng Huanhuan (Huawei)
+* Liu Liu (Huawei)
 
 # Logistics
 
@@ -23,3 +24,4 @@ This is the working repo for the MindArmour special interest group (SIG). This r
 * [Thursday June 04, 2020](./meetings/001-20200604.md)
 * [Friday July 03, 2020](./meetings/002-20200703.md)
 * [Saturday August 08, 2020](./meetings/003-20200808.md)
+* [Friday September 04, 2020](./meetings/004-20200904.md)

sigs/security/meetings/004-20200904.md

+# Friday September 4, 2020 at 2:15pm GMT+8
+
+## Agenda
+- Support parallelism in membership inference method.
+- Enhance the param-check of attack_config in  membership inference method.
+- Enhance the param-check of mutate_config in AI Fuzzer.
+
+## Conference links
+- https://imeeting.huawei.com/meeting/joinzoom?id=106116951&app=welink
+- Meeting ID：280361
+- Please install Zoom before the meeting.
+
+## Attendees 
+* Wang Ze (Huawei)
+* Lv Zhangcheng (Huawei)
+* Liu Liu (Huawei)
+* Liu Zhidan (Huawei)
+* Yang Yuan (Huawei)
+* Jin Xiulang (Huawei)
+* Duan Bo (Huawei)
+* Li Peng (Huawei)
+* Li Yanjun (Huawei), etc
+
+## Notes
+* Participants: Wang Ze, Liu Liu, Liu Zhidan, Yang Yuan, Jin Xiulang, Duan Bo,  Li Peng, Li Yanjun, etc.
+
+* The meeting video can be found:
+
+  *Post link after meeting*.
+
+## Action items
+* None.