Overview of how Digital Signatures works
Digital Signature India
The Digital Signatures require a key pair (asymmetric key pairs, scientifically related substantial numbers) called the Public and Private Keys. Generally as physical keys are utilized for locking and opening, in cryptography, the comparable capacities are encryption and decryption. The private key is kept secret with the holder normally on a safe media like crypto smart card or crypto token. The public key is imparted to everybody. Information encrypted by a private key must be decrypted utilizing the comparing public key.
So as to digitally sign an electronic document, the sender utilizes his/her Private Key. In order to verify the digital signature, the recipient uses the sender’s Public Key.
Let us understand how the Digital Signatures work in view of a case. Assume you are going to send the draft of an agreement to your legal advisor in an alternate town. You need to give your attorney the confirmation that it was unaltered from what you had sent and that it is truly from you.
- You copy-and-paste the contract into an e-mail note. Get electronic form of a document ( eg : word or pdf file).
- Using special software, you obtain a message hash (fixed size bit string) of the contract.
- You then use your private key to encrypt the hash.
- The encrypted hash becomes your digital signature of the contract and is appended to the contract.
At the other end, your lawyer receives the message.
- To make sure the contract is intact and from you, your lawyer generates a hash of the received contract.
- Your lawyer then uses your public key to decrypt the Digital Signature received with the contract.
- If the hash generated from the Digital Signature matches the one generated in Step 1, the integrity of the received contract is verified.