Phantom Cipher

Phantom Cipher is a powerful block cipher software with a solid reputation. This software has a block length of 128 bits and a key size of 256 bits. The detailed description of the cipher is available in the README file present in the package. However, the software is in the process of being converted into an HTML document.

In addition to the cipher, it also includes an implementation of a file encryption utility, which is currently available only on POSIX systems due to the platform-specific way it gets the password without echoing. The Phantom library has a hashing function that allows the users to produce keys from pass phrases, as well as encryption and decryption functions that operate Phantom in each of the three important modes, which are ECB, CBC, and CFB.

The installation process of Phantom Cipher is relatively straightforward. It requires the users to have an implementation of ANSI/ISO C for compiling the C sources. Furthermore, compiling the filecrypt.c requires POSIX.1 implementation. Nonetheless, any outdated UNIX versions without ANSI C compilers or libraries may incur difficulties during the compilation process. The Makefile assumes that the users have the GNU C compiler. However, they can always edit the Makefile as required and compile it by typing "make". Once the compilation is successful, an executable called "phantom" should result, which is the UNIX utility for enciphering and deciphering files.

Using Phantom Cipher in existing ANSI C programs is quite simple. The users can copy phantom.c and phantom.h into the folder where their project resides. They should include the phantom.h header file in any translation units that need to refer to a Phantom function or data type. They can then compile and link the phantom.c file along with the other source files of their projects. The filecrypt.c program may also serve as a programming example to assist with the process.

The phantom.c also contains a main() function for testing purposes. This is enabled by defining the TEST_MAIN preprocessor symbol before compiling phantom.c. When encrypting a file, the users can use the command "phantom -e [< infile > [ < outfile > [ < salt_phrase > [ < key_phrase > ] ] ] ] ". On the other hand, to decrypt a file, they can use the command "phantom -d [< infile > [ < outfile > [ < key_phrase > ] ] ]".

Overall, Phantom Cipher is a reliable and robust software that provides significant protection to the users' data. Its encryption and decryption modes can be utilized in various applications, and the library continues to provide premium services as a block cipher.