Bash Script Leet Text Convertor: How to get array to recognize spaces

Bash Script Leet Text Convertor: How to get array to recognize spaces

The issue with the code below is that I can not seem to get the array to
recognize when the text has spaces in it or not. I figured adding the ' '
value in the array would handle this, but I was wrong. I haven't found
much luck from searches about how to get an array to recognize spaces in
bash scripting.
#!/bin/bash
if [ "$1" == "-e" ]; then # if the cli argument is -e
OPT="encrypt"; # set the option to encrypt
elif [ "$1" == "-d" ]; then # if the cli argument is -d
OPT="decrypt"; # set the option to decrypt
else # else show the proper usage
echo "Usage - Encrypt text: ./l33t.sh -e text";
echo "Usage - Decrypt text: ./l33t.sh -d text";
exit;
fi
#creating an array for leet text and plain text
declare -a LEET=('ɐ' 'ß' '©' 'Ð' '€' 'ƒ' '&' '#' 'I' '¿' 'X' '£' 'M'
'?' 'ø' 'p' 'O' 'Я' '§' '†' 'µ' '^' 'W' '×' '¥' 'z' '1' '2' '3' '4'
'5' '6' '7' '8' '9' '0' ' ');
declare -a ENG=('a' 'b' 'c' 'd' 'e' 'f' 'g' 'h' 'i' 'j' 'k' 'l' 'm' 'n'
'o' 'p' 'q' 'r' 's' 't' 'u' 'v' 'w' 'x' 'y' 'z' '1' '2' '3' '4' '5' '6'
'7' '8' '9' '0' ' ');
echo -n "Please enter a string to $OPT: "; # asking for user input
read INPUT; # grab the input
while read letter; # for each character in the input (check the grep near
done)
do
for i in {0..37} # for each item in the array
do
if [ "$OPT" == "encrypt" ]; then # if the option is set to
encrypt
FIND=${ENG[$i]}; # the array to look through is the
plain array
elif [ "$OPT" == "decrypt" ]; then # else the array to look
through is the leet text array
FIND=${LEET[$i]};
fi
if [ "$OPT" == "encrypt" ]; then # if the option is set to
encrypt
if [ "$FIND" == "$letter" ]; then # if our character
is in the plain array
ENCRYPTED+=${LEET[$i]}; # Add to Encrypted
that values leet transformation
fi
elif [ "$OPT" == "decrypt" ]; then # else do the same thing
except with oposite arrays
if [ "$FIND" == "$letter" ]; then
ENCRYPTED+=${ENG[$i]};
fi
fi
done
done < <(grep -o . <<< $INPUT)
echo $ENCRYPTED; # echo the result