Do you want to protect data on your computer, or sent via email, from prying eyes? This page contains programs that do that.
Email encryption requires a "Certificate" to prove who you are. The certificate must be issued by a Trusted Authority. Microsoft email products (Outlook, Outlook Express and Live mail) can sign messages (to prove who sent them) and encrypt them using the certificate of the person you are sending to.
Certificates are provided by a Certificate Authority and until recently there has been a significant cost to obtain such a certificate. Recently however Comodo have been offering free certificates for email signing and encryption (for personal use only. There is a link to the Comodo site from Microsoft. They are a reputable company.
Follow the link and fill in the details. You will receive an email containing a link which will install the certificate on your computer. From then you can sign emails. If the recipient saves the name of the sender in their address book then the Public key is also saved with it.
To encrypt emails you need the Public Key element of a certificate from the recipient. This is contained in a signed message from the intended recipient and saved in the contacts list. A message encrypted with this public key can only be read by the posessor of the private key - the recipient.
Do you want to keep information private? This program allows you make a disk file (created by the program) appear as a new disk drive. All normal file accesses work. You can create folders within the "virtual" disk. The important thing however is that the virtual disk is encrypted. You have to enter a password/phrase to open the virtual disk. The encryption ought to be strong enough for most purposes and would prevent anyone who did not know the password from seeing the data.
TrueCypt is a Free Open Source encryption package. It creates one, or more, "disks" that, when the decryption key is entered, appear just like ordinary disk drives to the system. A bewildering number of encryption algorithms are supported. I am comfortable with the level of security provided by AES which is also one of the fastest.
The major benefit of this program, compared with private Disk Lite (see below), is that the pass phrase can be changed at any time. It is also possible to alter the drive letter that was allocated when the disk volume is created.
A traveller mode has been added which can be run without installation. due to the nature of the program
This program will encrypt a file. This can be generated as a self extracting exe file so that it can be decoded without having the software.
There are a number of well known encryption algorithms available.