Developer Notes

The Berlekamp–Massey algorithm is an algorithm that will find the shortest linear feedback shift register for a given binary output sequence. The algorithm will also find the minimal polynomial of a linearly recurrent sequence in an arbitrary field. I have used sage for computing this program. How to implement a Berlekamp–Massey algorithm? Explained with easy example # Berlekamp-Massey Algorithm #from __future__ import print_function s = [GF(2)(0), 0, 1, 0, 0, 0, 0, 0, 1, 1, 0] #input sequence n = len(s) C = [GF(2)(1)] B = [GF(2)(1)] temp = [] T = [] L = 0 N = 0 m = -1 print '----- n',n print '-----------------------------------------------------------------------' while N

Uwsgi - Nginx - Django - 499 and 502 errors fix

On rare occasions, we have been receiving 499 and 502 response codes from our higher environment server. Before that, we have added max-requests = 500 in UWSGI configuration to reduce the high consumption of physical memory. So we are suspecting add max requests would have caused the error. Loglines recorded in the uwsgi.log file. 10.115.21.68 - - [01/Jan/2020:04:09:50 +0000] "GET / HTTP/1.1" 502 157 "-" "check_http/v2.2.1 (nagios-plugins 2.2.1)" "-" 2020/01/01 04:09:50 [error] 30522#0: *22690 connect() to unix:///tmp/uwsgi.sock failed (11: Resource temporarily unavailable) while connecting to upstream, client: 10.115.21.68, server: , request: "GET / HTTP/1.1", upstream: "uwsgi://unix:///tmp/uwsgi.sock:" 10.115.13.75 - - [01/Jan/2020:04:09:48 +0000] "GET / HTTP/1.1" 502 157 "-" "check_http/v2.2.1 (nagios-plugins 2.2.1)" "-" 2020/01/01 04:09:48 [error] 30523#0: *22688 connect() to ...

10 lines python code to solve DLP (Discrete Logarithmic Problem) using Baby Step Giant Step Algorithm

10 lines python code to solve DLP (Discrete Logarithmic Problem) using Baby Step Giant Step Algorithm # Baby Step Giant Step DLP problem y = a**x mod n # Example 70 = 2**x mod 131 # Use SAGE for complex operations y = 70 a = 2 n = 131 s = floor(sqrt(n)) A = [] B = [] for r in range(0,s): value = y*(a^r) % n A.append(value) for t in range(1,s+1): value = a^(t*s) % n B.append(value) print A print B x1,x2 =0,0 for r in A: for t in B: if r == t: x1 = A.index(r) x2 = B.index(t) print x1,x2 break print 'the value of x is ', ((x2+1)*s - x1) % n # Answer

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