rkmylo

from __future__ import division
import hashlib
import requests
from datetime import datetime, timedelta

api_url = 'http://rfile.2017.teamrois.cn/api/download/{}/{}'

def totimestamp(dt, epoch=datetime(1970,1,1)):
    td = dt - epoch
    return (td.microseconds + (td.seconds + td.days * 86400) * 10**6) / 10**6

jFransham

Achieving warp speed with Rust

Contents:

• Number one optimization tip: don't
• Never optimize blindly
• Don't bother optimizing one-time costs
• Improve your algorithms
• CPU architecture primer
• Keep as much as possible in cache
• Keep as much as possible in registers

hellman

#-*- coding:utf-8 -*-
'''
DEF CON 2017 Quals - Godzilla (Reverse)
Timing attack on RSA decryption.
Based on http://www.cs.jhu.edu/~fabian/courses/CS600.624/Timing-full.pdf

Another solutions:
https://gist.github.com/nneonneo/367240ae2d8e705bb9173a49a7c8b0cd by b2xiao
https://gist.github.com/Riatre/caac24840b176cf843b3f66ad9a5eeaf by riatre

hellman

'''
Common-prime (in group order!) RSA with low private exponent.
p = 2ga + 1
q = 2gb + 1
N = p * q
phi(N) = 2gab
'''

from sage.all import *

elliptic-shiho

from sage.all import *
import itertools

# display matrix picture with 0 and X
# references: https://github.com/mimoo/RSA-and-LLL-attacks/blob/master/boneh_durfee.sage
def matrix_overview(BB, bound):
  for ii in range(BB.dimensions()[0]):
    a = ('%02d ' % ii)
    for jj in range(BB.dimensions()[1]):
      a += ' ' if BB[ii,jj] == 0 else 'X'

hellman

from sage.all import *

import re

active_bits = [
    0, 3, 4, 7, 8, 9, 10, 11, 14, 20, 21, 24, 25, 26,
    35, 40, 41, 43, 45, 46, 47,
]

code = """

gsilvis

#include <cassert>

#include <NTL/mat_GF2.h>
#include <NTL/GF2.h>

using NTL::GF2;
using NTL::mat_GF2;
using NTL::conv;

int g(GF2 x1, GF2 z1, GF2 x2, GF2 z2) {

logicmachine

CMAP2 Write-up

• 問題文: https://community.topcoder.com/longcontest/?module=ViewProblemStatement&rd=16833&pm=14534
• 順位表: https://community.topcoder.com/longcontest/stats/?module=ViewOverview&rd=16833

いま開催中のマラソンマッチ、c3.4xlarge（16コア）でストレージIOもありという環境での高速化コンテストだ。これは高速化を生業にしている某社のみなさまの出番では https://t.co/yIruowYFAI

— 今年は夏バテにならない (@tomerun) 2017年2月3日

<script async src="//platform.twitter.com/widgets.js" charset="utf-8"></script>

ということで参加してました。

yossorion

What I Wish I'd Known About Equity Before Joining A Unicorn

Disclaimer: This piece is written anonymously. The names of a few particular companies are mentioned, but as common examples only.

This is a short write-up on things that I wish I'd known and considered before joining a private company (aka startup, aka unicorn in some cases). I'm not trying to make the case that you should never join a private company, but the power imbalance between founder and employee is extreme, and that potential candidates would

hellman

from binascii import crc32

def lcg_step():
    global lcg
    lcg = (0x5851F42D4C957F2D * lcg + 0x14057B7EF767814F) % 2**64
    return lcg

def extract(val):
    res = 32 + val - 95 * ((
        ((val - (0x58ED2308158ED231 * val >> 64)) >> 1) +