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mrpdaemon / encdroid

Encdroid is an Android application for accessing EncFS volumes on cloud storage
GNU General Public License v3.0
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Improve PBKDF2 performance #22

Closed mrpdaemon closed 11 years ago

mrpdaemon commented 11 years ago

One of the Play Store reviews mentioned Cryptonite being faster when computing the password-derived key, so it is worthwhile looking into improving the performance. Perhaps building a module with the native client toolkit just containing an optimized method to do this computation would be appropriate.

mrpdaemon commented 11 years ago

Did some unscientific experiments on my box using encfs paranoid settings with ~1.1 million iterations of PBKDF2. Here are the runtimes:

encfs-java - 6.9 seconds (this is what encdroid is using) pbkdf2 - 6.7 seconds (very basic C implementation) pbkdf2-ssl - 2 seconds (OpenSSL implementation)

It looks like there's significant gains on using the OpenSSL implementation (which is probably what Cryptonite is using). I'll try to proof of concept a native library with openSSL and see if I can get that working with encdroid.

mrpdaemon commented 11 years ago

Fixed at 6de2781730a079c8e195cba1611b747455b0ecdb

On my Galaxy Nexus using "paranoid" settings of encfs-1.7.4 I get ~6 minutes of PBKDF2 before these changes. With these changes it only takes 40 seconds :)