Process Improvement for Digital Signature Application

My Summer Internship at L&T Power

Digital Signature and Digital Signature Certificates

Benefits of Digital Signatures

X509 Certificate

X.509 is a standard defining the format of public key certificates. An X.509 certificate is a digital certificate that uses the widely accepted international X.509 public key infrastructure (PKI) standard to verify that a public key belongs to the hostname/domain, organization, or individual contained within the certificate. The X.509 certificate is either signed by a publicly trusted Certificate Authority like DigiCert, Sectigo, GlobalSign, etc. or self-signed. When a certificate is signed by a trusted certificate authority, or validated by other means, someone holding that certificate can rely on the public key it contains to establish secure communications with another party, or validate documents digitally signed by the corresponding private key.


The Project is based on the concept of Pdfs and other documents being self signed with Digital Certificates of required signatures through the Subject Key Identifier assigned to the signer by a ASP .NET C# based console application. In a MNC, the efficiency in signing and authenticating numerous documents by multiple Authorities is very crucial. The Application is designed to precisely sign a directory of multiple file or documents matching its correct signature certificate at once.

My Application

As a Summer Intern for L&T Power, I created a console application that collected all the Documents required from the directory and signed it pairing with the right digital certificate stored in the system. Hence Multiple files can be signed at a time with precision. Unfortunately due to the (COVID-19 situation)Lockdown, I was unable to get access to their database and system resources. So, I created my own database using MySQL Workbench and used it in to extract certificate data for signing. The Flowchart displaying the working of the Application is shown below:

Sample Digital Certificate
Sample Document which is Digitally Signed

In Conclusion

Problem solving, Critical thinking and desire to keep learning got me through my course of this Internship. It was a Journey talking me from exploring new platforms and technologies to implementing them successfully to create a utility. My skills in C# and SQL sharped as I learnt a lot going through the documentations of libraries and other works relating my project

Be grateful. For anything and everything you do in the workplace. Treat every interaction and lesson as a blessing.



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Darshil Patel

Summer Intern at L&T Power | Application Developer | Flutter Developer | ML Enthusiast