RSATool, RSA public key encryption algorithm tool.

This Windows program I Jiri Kocian created is very useful breaktrough cryptoanalytic utility for generating keypairs, calculating private exponent from P, Q primes and Factorisation of the N modulus to primes P, Q. Now the program also encrypts and decrypts data.

The user enters the keysize in bits, public exponent E and Number base and then from this information keypairs can be generated. The program is also useful for Calculating private exponent D from any P, Q primes entered in edit boxes. The program is also very interesting because of the feature to factorise modulus N to primes P and Q using Quadratic Sieve algorithm. Program also can encrypt and decrypt any text or binary data entered in the Encryption / Decryption dialog text box. Encrypted data can be saved to hard disk in the binary form. Program has a feature to save generated keys. Program also can load the saved keys from files. And neccessary note, please be patient using this program, generating keys with long keysizes like 4096 bits or even 8192 bits or more takes some time in minutes, factorisation is even more time consuming process.

Release notes:

Since the version 1.18 there is not needed to download primes file, the rest of the keys are downloaded

Since the version 1.17 there is repaired small bug now the main dialog not close when enter is pressed and the default keylength is set to 2048 bits.

Since the version 1.15 in the Encrypt/Decrypt dialog box, there's special feature to choose public exponent E or private exponent D for Encryption.

Since the version 1.10 encrypted data are also saved in encrypted.hex file.

Since the version 1.09 the keypair can be now loaded from saved files into program.

Since the version 1.08 the primes P and Q are also saved into the file called primes.p12 when the button Save generated keys clicked.

Since the version 1.06 the program has a feature to save the generated keypair into the files public.key and private.key.

Since the version 1.04.03 the load of binary encrypted data is supported.

Since the version 1.04 there's Encrypt / Decrypt dialogbox included in the program.

In future versions there will be then new dialog box for encryption and decryption of any binary or text data using generated keys.

Program is tested in Windows 7/8.1/10.

You may simply download the software, then unzip and put the exe to any folder on your hard drive, and start to use. No installation is required. The download does not contain any virus, spyware, adware or malware.


Executable only:


License Agreement:

Program RSATool is free for noncomercial usage. Commercial users will pay for the software. You are granted unlimited rights to use RSATool. All files must remain intact and unmodified from the original as distributed by the author.

Disclaimer of Warranty


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RSATool created by Jiří Kocián Copyright © 2017. All rights reserved.

On the Web since 1.7.2003.

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