DEV Community: Roger Doss

Perl Stream Cipher

Roger Doss — Wed, 16 Aug 2023 19:12:21 +0000

A stream cipher is a type of cipher that encrypts each bit. I used this design to implement a cipher in Perl that uses SHA-3 as the basis for the pseudo-random bits. The code gets a random set of numbers as a key from random.org, and then encrypts them using a password on disk for key storage. The on disk algorithm is AES.

The stream cipher then uses the random key to encrypt by xor function of each byte of the plain text, to create the cipher text. When it needs more bits, it re-hashes the key using SHA-3.

The algorithm can be run using:

perl -I. ssc_main.pl input.plain output.cipher

The implementation is here:

StreamCipher

Perl script to search for large primes

Roger Doss — Thu, 10 Aug 2023 16:28:40 +0000

Experimental code to search for random probable primes for research.

The code will create multiple instances of the randPrime_thread.pl script which will search for a random prime starting with a random number. Note that each of the perl scripts run has its own threads. sleep calls are needed so as not to overheat the processor. The processes should end when one of the threads writes a file:

.randPrime.search.done

And this happens when one of the threads discovers a probable prime. At the same time, the discovered prime is written to the ./data directory.

The largest prime generated so far was 9800+ digits large.

You can control the size of the prime you are looking for by specifying the number of bits.

The code and data are here.

Perl tags program

Roger Doss — Tue, 08 Aug 2023 22:30:46 +0000

Recently, I got some free time to tinker with some side projects. One of which is a Perl based tags program for VIM. It's a work in progress. The idea is to explore regular expressions and parsing out source files of different languages which I think Perl is good at. Feel free to check it out on my github