The concept of secure deduplication is interesting for both research and industrial community because of reducing high costs in cloud computing environment (e.g., Amazon S3, Dropbox, OwnCloud, TeamDrive, Box, OneDrive (formerly SkyDrive), Google Drive, DepSky, and SugarSync). The first solution is to apply convergent encryption mechanism which was designed by J.R. Douceur and other colleages in 2002.
The data in this method is encrypted using a symmetric encryption scheme with a key which is deterministically derived from the hash of the data content. The convergent encryption mechanism is actively used by commercial CSPs like Amazon S3, Dropbox, Google, and Bitcasa . Note that convergent encryption does not provide semantic security because of content-guessing attacks using the deterministic nature of the content hashing.
In a public blockchain, the data can be plain or encrypted. Therefore, possession of an existing data on the chain can be achieved in two cases.
- In case of data is plain, any user can claim to posses the data on the chain. This is simply cloning data into repository of the new repository.
- In case of encrypted, the user who wants to posses the data on the chain should provide a proof of the data on the chain.
In a decentralized storage solution as Stashware it’s vital that data is replicated but avoid unnecessary duplication of data, such as the same content under different names. Ensuring both the accuracy and integrity of the data and privacy if they are encrypted.
Store your life: The longest journey begins with Stashware