Cryptr

Encrypt and Decrypt any file for secure file sharing across the internet. Tested with .txt .png .gif and .mp4. An example is given in the PDF file.

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Compile with: $ javac Cryptr.java

1. Generating a secret key

   $ java Cryptr generatekey <secret key file>
   

2. Encrypting a file using a secret key

   $ java Cryptr encryptfile <file to encrypt> <secret key file> <encrypted output file>
   

3. Generate Key Pair

   $ openssl genrsa -out <private key name>.pem 2048
   $ openssl pkcs8 -topk8 -inform PEM -outform DER -in <private key name>.pem -out <private key name 2>.der -nocrypt
   $ openssl rsa -in <private key name>.pem -pubout -outform DER -out <public key name>.der
   

4. Encrypting a secret key using a public key

   $ java Cryptr encryptkey <key to encrypt> <public key to encrypt with> <encrypted key file>
   

5. Decrypting a secret key using a private key

   $ java Cryptr decryptkey <key to decrypt> <private key to decrypt with> <decrypted key file>
   

6. Decrypting a file using a secret key

   $ java Cryptr decryptfile <file to decrypt> <secret key file> <decrypted output file>
   

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• Class project for Rutgers University's Computer Security class