Is it possible to password protect documents and files?

Question

Is it possible to make it so it is impossible to open certain text/picture/video files without first typing in a codeword? If so, how?

Answer 1

Encryption does not hide files, it just makes the contents unreadable. Many people encrypt their hard drives but the problem is if you are using Windows to encrypt all the files on your HDD the password is saved on the computer. The use of a third party encryption program is what any person should get.

Truecrypt is a free software that is secure.

File encryption aka cryptography, is the act of transforming sensitive data through an algorithm to make the file unreadable. Basically data is collected divided into chunks, put through separate algorithms, and put back together.

Example:

Lets say you want to encrypt "123" easy right.

We will first split this string up. (String refers to a instance of text)

So...

1

2

3

Put them through an algorithm

1+ 5 = 6

2 + 4 = 6

(3 + 13) / 8 = 2

Put them back together...

662

Now nobody will know what you wrote down unless they have the algorithm. It is much more complicated, but that is the idea.

Plain Text:

This text is readable...

Encrypted Text:

cMKRSA2qJUm9/8/4Lhstna+k+E0IyClKqCnkiP...

Now there are many forms of encryption:

The most commonly used is AES-256 bit encryption

+++This means there can be up to 32 characters in the password or 2^256 possible combinations

The newest is Diamond2-2048 bit encryption.

+++This means there can be up to 126 characters in the password or 2^2048 possible combinations

The only way to decrypt the file is:

1) If you have the original program that encrypted file,

2) If you have the algorithm used to encrypt the file,

3) You can reverse engineer the program used to encrypt the program in order the file the algorithm.

Even then, it is nearly impossible for an attacker to crack and decrypt the file.

Remember, the longer the key is the longer it will take to crack the file.

Even with these two types it will take 5.5 million years to crack AES (the standard in encryption)

Types of attacks (two most common):

Brute Force and Dictionary attack.

Strong Password:

1) Do not use words (hey, tree, feather, etc.

2) Mix upper/lower -case, with numbers and extra characters (a, A, 1, $)

3) Make the passwords long and unique

Good luck.

Regards,

Dane