Craig Westcarr hit the post shortly after the break and also put a good chance over when well placed as Crawley's winless league run was extended to six games.
Smith believes the hat-trick of shut outs has increased confidence ahead of Tuesday's clash at Sheffield United and said: "We had some really good chances in the second half on a bit of a pudding of a pitch.
"On the whole it's a tough place to come and not many teams get a point and a clean sheet here.
"It's great to get three successive clean sheets and our keeper and back four have been excellent.
"It gives you more chances to win games and although going to Sheffield United will be tough, we have got increased confidence."
Smith was disappointed that his side's good play was not rewarded by three points.
He added:"While we were creating some good chances in the second half our keeper didn't make a save of note to be honest, where as their keeper was man of the match.
"It's up to us to get better all the time and keep working at it.
"Both teams looked really organised, both like to play and it was interesting that Romaine Sawyers was well held by Dannie Bulman all game."
- Sports & Recreation
- Sheffield United