# PASSAT: Single Password Authenticated Secret-Shared Intrusion-Tolerant Storage with Server Transparency

**Authors:** Kiavash Satvat, Maliheh Shirvanian, Nitesh Saxena  
**arXiv:** [2102.13607](https://arxiv.org/abs/2102.13607)  
**Date:** 2021-02-26  
**Summary page:** https://www.summarizepaper.com/en/paper/2102.13607v1/

## Key points

- PASSAT is a practical system designed to enhance the security of files stored in public cloud storage.
- PASSAT operates transparently to cloud servers and enables users to securely store and access their files using a single master password.
- It utilizes a fast and lightweight XOR secret sharing scheme to distribute users' files among multiple publicly available cloud platforms.
- This approach improves confidentiality and enhances availability by ensuring data remains accessible even if one platform becomes unavailable.
- PASSAT guarantees data integrity by preventing unauthorized modifications or tampering through its use of secret shares.
- To authenticate users across multiple platforms, PASSAT stores authentication credentials on a password manager protected under the user's master password.
- The authors implemented PASSAT using a (2, 3)-XOR secret sharing scheme and integrated it with popular storage providers like Google Drive, Box, and Dropbox.
- Evaluation confirms that this approach efficiently enhances confidentiality, availability, and integrity without requiring any server modifications.

## Summary

This paper introduces PASSAT, a practical system designed to enhance the security of files stored in public cloud storage. PASSAT operates transparently to cloud servers and enables users to securely store and access their files using a single master password. It utilizes a fast and lightweight XOR secret sharing scheme to distribute users' files among multiple publicly available cloud platforms. This approach not only improves confidentiality but also enhances availability by ensuring data remains accessible even if one platform becomes unavailable. PASSAT also guarantees data integrity by preventing unauthorized modifications or tampering through its use of secret shares. To authenticate users across multiple platforms, PASSAT stores authentication credentials on a password manager protected under the user's master password. The authors implemented PASSAT using a (2, 3)-XOR secret sharing scheme and integrated it with popular storage providers like Google Drive, Box, and Dropbox. Their evaluation confirms that this approach efficiently enhances confidentiality, availability, and integrity without requiring any server modifications. In conclusion, presents a practical new paradigm for enhancing security in . By leveraging  and utilizing , it provides improved confidentiality, availability, and integrity for users' sensitive data.