Locking SDHC Memory card on Samsung Galaxy 2 I have stored an important document on the SDHC card on my Samsung Galaxy 2 phone (so that I can edit it on the go). I don't want others to access this file or document without my permission.

I know I can lock the phone but this option means that nothing could be done on the phone unless it is unlocked.

I want others to still make calls from my phone but not be able to access the memory card. (Letting others use my phone is an internal arrangement i.e. so that there is one point of contact when we are travelling together)

Is there a way to lock the memory card (with a password) but leave the phone unlocked?
You cant lock, in your definition, the sdcard or one file. But you have some ways to protect your file. 


Store it in a password protected Zip file.
Encrypt your sdcard
Use a AppLocker to lock the apps they are needed to view / edit the file.
Use BoxCryptor.


The only safe way is, to encrypt it. If you lock your sdcard with a software, the thief can easily connect it to a pc and steal the file or even steal the whole sdcard.