Digital Signage

Digitally signing files provided a way to verify that a file sent is the same when received and guarantee who the sender is (nonrepudiation).

Scripts to digitally sign files:

• asymmetric_keygen.sh # Will generate a private.pem key and public.pem key
• digitally_sign.sh # To run before sending. Will digitally sign a file passed as a parameter with the generated private key
• digitally_verify.sh # To run on receiving end. Will verify with public key the author and integrity of the document

Setup:

 git clone https://github.com/anthony-albertina/digital-signage.git
 chmod -R +x digital-signage # Makes the scripts executable

Example:

In this example, Alice would digitally sign a provided file. This hashes and encrypts the file with her private key. After sending the file and digital signature to Bob, he would verify the signature by hashing the original file, and decrypting the digital signature with Alice's public key. If the hashes are the same, then we can guarantee the integrity of the file.