Encrypting at home and decrypting while traveling

[Rene]

I’m trying to understand the functionality and possibilities of using AxCrypt (free) in specific circumstances.  I’ve installed AxCrypt on my desktop at home and have encrypted a file (Excel) using AxCrypt.  I then sent this file to myself by email (to my own email account).  What I want to know is how I can access this file while traveling without having to have AxCrypt installed on the computer at which I am trying to access this file.  So suppose I’m in a hotel away from home that offers use of a desktop that has Excel installed on it.  I could access my email from there and download the AxCrypt protected file to that computer (or to a USB stick that I have, which I would attache to that computer).  Now is there a way to open that file without having AxCrypt installed on the hotel computer, since the hotel does not allow programs to be downloaded and installed on its computers?

Thank you

[Solomon]

If you’re using Microsoft Excel the simplest solution is to use the integrated encryption that Microsoft provide. It’s extremely secure and doesn’t require you to install any special software. For instructions click here.

AxCrypt is primarily for files that you want to share with friends/colleagues or if you want to keep your files in the cloud. Because AxCrypt is proprietary the recipient needs to have AxCrypt installed on the destination computer.

[Rene]

Dear Salomon,

Thank you for the quick, clear, and useful response.

My main concern is indeed with the strenght of the encryption process used.  When you say that the integrated encryption provided by Excel is “extremely secure”, is this at the level of AES-256 and if not how much weaker than that (if there is a way to decribe that).

Many thanks again.

Regards,

Rene

[Solomon]

There’s no need to be concerned about Microsoft’s encryption. By default Microsoft Office uses AES-128 bits with 100,000 iterations – this is extremely secure [source].

How long will AES-128 take to crack? Well, that depends upon the length of your password but to give you an idea about 14 billion years according to one researcher [source]. I estimated it to be about 12 billion years.

So comparing AES-128 to AES-256 is pointless because in reality neither are going to be cracked any time soon. It’s like asking which is easier to swim: the Atlantic or Pacific?

One thing to bear in mind though: in your situation you’re seriously compromising your security by opening your files on a hotel (i.e. non-trusted) computer. If there’s a key-logger installed, they’ve got your password. If there’s file recording software installed, they’ve got your file and your password. If there’s security cameras overlooking your screen, they’ve got the information. No amount of encryption will help you here.

[Rene]

Thanks again for the very useful info; also the vulnerabilities to opening files on public computers.  I will stay away from that habit!

Best regards,

Rene

[Solomon]

I don’t know what your job is Rene but you need to be aware that hotels offering free facilities should be treated with the utmost of suspicion.

Have a quick watch of this eye-opening video.

[Rene]

Wow, thanks.  Pretty scary.

There’s now one person less using any public computers!

Regards,

Rene

[Author]

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