The author says, "To ensure no compromise in security, the file server should return a null hash for any object on which the client only has permission to read the meta-data."
Can you please clarify this statement. Does it mean that if a client only has read permissions, the look-aside caching is not used and the file contents have to be fetched from the server?
If the application modifies files which are present in the lookaside cache, even by a small amount then that file needs to be fetched form the server. So if the application is write intensive then with the lookaside cache application will experience performance problem because of lookaside caching itself... this may be aggravated by low network bandwidth..
Towards the end of section 4, the author has stated that the use of hashes can leak information by fetching the SHA-1 Hash by a malicious server and it can allow it to read the client's cache. Here, the author makes an assumption that the use of lookaside caching will only be done with Trusted servers. But then there is a threat to the user's data if a malicious server sneaks in. So, how can the author say that going in for a simple design was a conscious decision? If the author knows in advance that a malicious server can read a client's cache, they should have made the design better to account for this. Are there any traces of further work in this regard?
The author says, "To ensure no compromise in security, the file server should return a null
ReplyDeletehash for any object on which the client only has permission to read the meta-data."
Can you please clarify this statement. Does it mean that if a client only has read permissions, the look-aside caching is not used and the file contents have to be fetched from the server?
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ReplyDeleteIf the application modifies files which are present in the lookaside cache, even by a small amount then that file needs to be fetched form the server. So if the application is write intensive then with the lookaside cache application will experience performance problem because of lookaside caching itself... this may be aggravated by low network bandwidth..
ReplyDeleteTowards the end of section 4, the author has stated that the use of hashes can leak information by fetching the SHA-1 Hash by a malicious server and it can allow it to read the client's cache. Here, the author makes an assumption that the use of lookaside caching will only be done with Trusted servers. But then there is a threat to the user's data if a malicious server sneaks in.
ReplyDeleteSo, how can the author say that going in for a simple design was a conscious decision? If the author knows in advance that a malicious server can read a client's cache, they should have made the design better to account for this. Are there any traces of further work in this regard?