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Python or C or Python+C ?

Python C

We present a discussion on the use of the C and the Python languages and the use of Python calling a C library. Some arguments are general while others arise from the specific application of modifying a .csv (text) file.

Calling C from Python

Python C

Whatever the reason you would like to call C functions from Python, one approach is presented here and consists in creating a C dynamic library, compiled as a .so module and accessing the library thanks to the ctypes package of Python. Explanations are given step by step and stand for a Linux environment (tested with Ubuntu20.04).

Creating a dynamic library in C

C

C libraries are handy for distribution of programming work or for structuring a large development into units. In the specific case of Python programming, a C dynamic library can be a solution for a missing Python equivalent or if performance in execution time is a concern. We explain hereunder with an example the steps necessary to write a dynamic (shared) C library in Linux (tested on Ubuntu20.04). Another blog describes how to call a C dynamic library from Python ([https://cylab.be/blog/235/calling-c-from-python]).

What is VoWiFI ("Wi-Fi Calling") ?

1. What is VoWiFi ("Wi-Fi Calling") ?

Mobile Phones: Should you be afraid of disclosing your IMSI ?

SS7

The smartphone has become so important in daily life that users should be concerned about its security. We try to explain here some reasons to be or not to be afraid about disclosing the IMSI, the subscriber identity number used in the global telecommunication network.

A bit of PIL for bit plane display

Python Steganography

Displaying image bit planes, in particular less significant ones, is an important task to reveal some image artefacts due to image degradation or manipulation. In particular, the Least Significant Bit (LSB) of pixel values is heavily used in steganography to hide messages in a cover image. We will see in this blog how to use the Python Imaging Library (PIL) to save and display an image containing some specified bit planes of a given image.

SMS-based 2-Factor Authentication is insecure !

SS7

The US National Institute of Standards and Technology (NIST) has declared in its Digital Authentication Guideline that SMS-based two-factor authentication should be banned due to security concerns [End of SMS-based 2-Factor Authentication; Yes, It's Insecure!]. We explain why in this blog.