On 25/07/2011 14:25, Jan Peters wrote:
Hi there, we are a follow-up project to a student's group at Ruhr-University Bochum, Germany, which tried to integrate a functionality into Subversion to allow users to encrypt all their data on the client-side, before committing and to decrpyt while updating.
If I understand you correctly, I have a feeling that this is fundamentally a bad idea, since Subversion stores data using diffs. Since encrypted data looks identical to random binary data, all diffs will necessarily be as large as the file being committed (or 2x the size possibly: 1x to remove the old file + 1x to add the new file). Compression won't help either, again because encrypted data looks random. So storage requirements for the repository will increase rapidly, and client side performance will be very slow since a trivial svn update that only changes 1 line will require fetching the whole changed file from the server. Additionally, repo browser change viewing won't work either. OTOH, some VCS systems got away working like this for years!
If you need an encrypted repository, for which only the clients hold the necessary decryption keys and which never has access to any decrypted data (e.g. in the server process), I can't think of another approach though.
Kind regards, Tom
