Generate the sha256 hashes of all six digit OTPs in 970 seconds (16 minutes, 69 MB)

gen-otp-sha256.sh

#!/bin/bash

OUTFILE="otp-hashes.csv"

function gen_hash() {
  otp=$1;
  hash=$(echo -n $otp | sha256sum | awk '{print $1}');
  echo "$otp,$hash" >> $OUTFILE;
}

start=$(date +%s)
for otp in $(seq -w 000000 999999); do
  gen_hash $otp &
  echo "$otp";
done
wait

end=$(date +%s)
elapsed=$(( end - start ))
echo "Elapsed time: $elapsed seconds"