# Welcome

Welcome to crypto-toolkit!

**Warning!** This toolkit is to be used as a demonstration, NOT as a tool for actual encryption!

# License

The MIT License (MIT)

Copyright (c) 2015 Mariusz Skoneczko

Permission is hereby granted, free of charge, to any person obtaining a copy

of this software and associated documentation files (the "Software"), to deal

in the Software without restriction, including without limitation the rights

to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

copies of the Software, and to permit persons to whom the Software is

furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all

copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE

SOFTWARE.

# Caesar cipher

The Caesar cipher is a simple substitution cipher which, as the name suggests, was used by Julius Caesar.

Message:

Key: (number)

Output:

Output

# Vigenere cipher

If the Caesar cipher was considered one-dimensional, the Vigenere cipher is two-dimensional. It was put into practice by Blaise de Vigenere.

Message:

Key: (letters)

Output:

Output

# RSA

RSA was invented by Ron Rivest, Adi Shamir and Leonard Adleman. It is the most commonly used public-key cryptosystem as of this writing.

### Key generation

Starting at to the power of get the next prime. Based off that, get another prime starting at the product of the prime and

Public key (share!):

Private key (keep secret!)

```
```

### Encryption/Decryption

Message:

Public key:

Private key:

Result

# Diffie-Hellman key exchange

The Diffie-Hellman was one of the first solutions to the problem of key exchange. It allows two parties to agree on a key over an insecure channel.

### Public prime and base

Use RFC3526 standard:

### Private key

Your private key must be a number between 1 and 2^{(bits - 1)}

### Generate public key

Make sure that the steps above are complete, and then press the button below.

### Agree on final key

Send the public key to the other person. Get them to give you their public key.

Now you can arrive at the same key!

This key can now be used for symmetric key algorithms.

This is a basic Caesar cipher cracker that shows all possible results from a given ciphertext. Fill in the textbox with the ciphertext, and press the crack button to see all possible plaintext messages.

Output