How to use CryptSecure

USER GUIDE

How to Use CryptSecure

Complete step-by-step instructions for setting up secure encryption, exchanging keys, and protecting your communications.

Understanding Public & Private Keys

CryptSecure uses asymmetric encryption. Each user has a key pair: one public, one private. Understanding this is essential.

PUB

Public Key

Share freely with anyone. Others use your public key to encrypt messages to you. Safe to send via email or any channel.

PRI

Private Key

Keep secret — never share. Only you can decrypt messages sent to you. Losing it means permanent loss of access to encrypted data.

Your Message
Encrypt with Recipient’s PUBLIC Key
Send via Any Channel
Recipient Decrypts with PRIVATE Key

Initial Setup

Complete these steps once to configure CryptSecure on your computer.

1

Launch the Application

Open CryptSecure from the Start menu or your chosen location. No installation is required — simply run the executable.

2

Set Your Key Storage Location

Use the pull-down menu to specify where your keys will be stored (e.g., C:\KeyStorage). This only needs to be done once — CryptSecure will remember your preference.

TIP: Choose a location you can easily back up, such as an encrypted USB drive or a secure folder.
3

Choose Your Key Strength

Select the RSA key strength before generating your keypair. Options are 1024, 2048, or 4096 bits. Higher values provide stronger security but slightly slower performance.

RECOMMENDED: Use 2048 bits for general use or 4096 bits for maximum security.
4

Create Your Keypair

Click the Create button to generate your public and private keys. Both files (.pem) will be saved to your designated key storage folder.

CRITICAL: Never share your private key. Store it securely and create backups. If lost, encrypted messages cannot be recovered.

Exchanging Public Keys

Before you can communicate securely, you and your contacts must exchange public keys.

1

Locate Your Public Key

Navigate to your key storage folder (e.g., C:\KeyStorage). Find your public key file — it will have a .pem extension and typically contains “public” in the filename.

2

Send Your Public Key

Email or message your public key file to everyone you wish to communicate with securely. You can use any channel — email, messaging apps, file sharing — public keys are safe to share openly.

REMEMBER: Only share your PUBLIC key. Your private key must remain secret and secure.
3

Receive Their Public Keys

Ask your contacts to send you their public keys via email or any messaging system. Save these files to an accessible location.

4

Import Public Keys

Navigate to Keys → Manage Keys → Add New Key. CryptSecure will ask if you wish to add a keypair — click Yes to create a new keypair for yourself, or click No to import a contact’s public key. If you select No, a dialog box will appear where you can browse to and select your friend’s public key file. Once imported, their name will appear in the recipient dropdown menu.

TIP: Keep your contacts’ public keys organized by saving them with clear names (e.g., “Steve_public.pem”) before importing.

Encrypting a Message or File

Send secure communications that only your intended recipient can read.

1

Select the Recipient

From the leftmost dropdown menu, choose the public key of the person you’re sending the message to. This could be “Steve,” “George,” “Sam,” or any contact whose key you’ve imported.

REMEMBER: You encrypt with the recipient’s PUBLIC key. Only their private key can decrypt it.
2

Enter Your Message

Type or paste your message into the top text box. You can also use the Load feature to import text from a file.

3

Attach Files (Optional)

Click the Attach File button to add any document, image, or file you wish to encrypt along with your message. Any file type is supported.

4

Add a Passphrase (Optional)

For additional security, enter a passphrase that you’ve pre-arranged with your recipient. This adds a second layer of AES encryption on top of the RSA encryption.

NOTE: The passphrase is optional — your message is already strongly encrypted with RSA. Use it for maximum security or when required by your security policy.
5

Encrypt

Click the Encrypt button. Your message (and any attached files) will be encrypted. The encrypted output appears in the bottom text box.

6

Send the Encrypted Message

Copy the encrypted text or save it as a file. Send it to your recipient via any channel — email, chat, file transfer — security no longer depends on the transport method.

Decrypting a Message or File

Open encrypted communications sent to you by your contacts.

1

Receive the Encrypted Message

When you receive an encrypted message via email, chat, or any other method, copy the encrypted text or save the encrypted file to your computer.

2

Paste the Encrypted Content

Paste the encrypted text into the bottom text box of CryptSecure. Alternatively, use the Load feature to import from a file.

3

Select Your Private Key

From the rightmost dropdown menu, select your private key. This is the key that corresponds to the public key the sender used to encrypt the message.

4

Enter the Passphrase (If Used)

If the sender used a passphrase, enter the same pre-arranged passphrase. If no passphrase was used, leave this field empty.

5

Decrypt

Click the Decrypt button. The decrypted message will appear in the top text box.

6

Save Attached Files (If Any)

If the encrypted message contained file attachments, a dialog box will appear prompting you to save them to your desired location.

7

Read or Save Your Message

Copy the decrypted text from the top text box or use the Save feature to export it to a file.

Best Practices

Follow these guidelines to maintain the highest level of security.

PRI

Protect Your Private Key

Never share your private key with anyone. Store it on an encrypted drive and keep secure backups in a safe location.

BAK

Back Up Your Keys

If you lose your private key, all messages encrypted with your public key are permanently unrecoverable. Maintain secure backups.

Verify Key Authenticity

When receiving public keys, verify them through a separate channel (phone call, in person) to prevent man-in-the-middle attacks.

AES

Use Strong Passphrases

When using the optional passphrase feature, choose something long and unique. Exchange passphrases via secure channels only.

Quick Reference

CryptSecure Cheat Sheet

PUB

Public Keys

Used to ENCRYPT messages TO someone. Safe to share openly.

PRI

Private Keys

Used to DECRYPT messages sent to you. Keep secret — never share.

Left Dropdown Menu

Select recipient’s PUBLIC key (for encryption).

Right Dropdown Menu

Select YOUR PRIVATE key (for decryption).

TOP

Top Text Box

Input plain text (encrypt) or view decrypted output.

BTM

Bottom Text Box

View encrypted output or paste encrypted input for decryption.

Ready to Get Started?

Download CryptSecure and start protecting your communications today.