Digital Signature and its uses

Digital Signature and its uses

Similar to how a handwritten signature is used to authenticate the document’s originality and the signee’s identity, digital signatures are a popular way of doing this with emails and other text documents sent over the internet. 

A digital signature is, in essence, a string of encrypted hashed numbers sent along with the original message with the intent of using the sent digital signature to check against the sent document for signs of any tampering. 

How Does it Work?

Digital signatures work on the basis of a public-private key encryption system, like RSA (Rivest–Shamir–Adleman) technique, where the public key is sent to the receiver via the internet while the private key remains undisclosed with the user who generates it. In the case of digital signatures, a hashing algorithm is used to first generate the sender’s digital signature hash number based on the original text of the message, the sender’s details and even the time and place of sending. 

This hash number along with the hashing algorithm used is then encrypted using the private key, and this encrypted data is sent to the receiver along with the email to the receiver. The receiver then decrypts the hash signature number with the public key he was provided and generates the signature once again using the copy of the email he received. 

If the email was altered even slightly in transit, the resulting hash number would be very different from the one sent and so the user would immediately know the email is inauthentic and cannot be trusted. 

Uses of Digital Signature

A digital signature is one of the best ways to check the integrity of the document sent over the internet; if even a character had been moved out of place, the digital signature system would be able to immediately detect this change and report the document as tampered. Digital signatures can also be used to authenticate the sender of a document since all senders have a unique private-public key encryption system and no two users are able to generate the same system. Besides confirming who the actual sender is, digital signatures can even be used as a countermeasure against repudiation; a sender cannot deny having sent an email if the signature on the email matches his unique one. All of the qualities of a digital signature makes it a great tool for use in the finance and banking industries, where authentication and integrity are important aspects of any business deal or transaction. 

Types of Digital Signature

There are three types of digital signatures, namely Class 1 to 3 and they differ from one another in the strictness of the system and the relative security they provide. 

  • Class 1 digital signatures are only used to authenticate the sender’s email address and are commonly used to communicate on a professional level by employers with their workers. 
  • Class 2 digital signatures validate the sender’s identity are issued by a central authority, making them a good choice for more sensitive tasks like filing income tax returns.
  • Class 3 digital signatures provide the highest form of authenticity and these are only issued in person with rigorous background checks and validations having already been taken.

Why are Digital Signatures growing in popularity?

The need for validating a document’s sender and authenticity is ever-present in the corporate world and with the ever-increasing shift towards conducting more and more of our business online, traditional methods of checking a document’s integrity are quickly becoming obsolete. This has logically led to the rise in popularity of Digital Signatures and their use is being readily adopted by corporations all over the globe

Many companies are also choosing to adopt the digital signature system because of the higher security it offers; after all, a digital signature is much, much harder to replicate than a traditional handwritten signature.

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