How Digital Signatures and Encryption Work

Moving from paper to an electronic business model is in everyone’s interest, because online communication not only saves time and resources, it offers new possibilities that would have been difficult to implement prior to the expansion of the Internet.

However, there is still room for improvement when it comes to switching from traditional to online interaction. For one, many businesses and government agencies are reluctant to fully switch to electronic communication and file sharing, primarily because of the not completely reliable methods of securing sensitive e-documentation.

There’s been much advancement in this direction with password-protected documents and the invention of electronic encryption and digital signatures. It seems that we are very close to reaching a model of online communication that will guarantee safe document transfer and reliable authentication of digital identities.

Encrypting Documents for Safer Digital Interaction

With encryption systems, you generally have three options:

To illustrate the use of encryption methods with a digital signature, we'll use the example of Susan who wants to send you a signed document.

First, Susan creates her message. Once it's finished she uses her software to encode the message data into a smaller version through a process called "hashing". This hashed version is called a message digest. Next, the message digest is, in turn, encrypted with her private key that is specific only to her. The resulting encryption of the message digest is Susan's digital signature. Lastly, this digital signature is attached to the original document and sent to you.

On receiving the document, your computer software (with Susan's public key code) verifies the document and signature by verifying the message digest. The signature is first decrypted using Susan's public key. If successful, this process would change it back into its message digest form, confirming for you that it was hashed with the corresponding private key. In addition, your software would check the document by hashing the document data into a message digest with the public key, testing to see if the digest matches the one resulting from the signature decryption.

Although this process may seem complicated, on screen the validation process is done through the simple click of a button.

Encryption is only one way to achieve higher level of security when sending documents via the Internet. Another popular method among business professionals is sending secure PDFs.

With the help of Investintech’s Able2Extract PDF Converter users can create secure PDFs by setting passwords and file permissions when sending and sharing sensitive files online.