Griffiths told the club's website: "I'm delighted to be here. I'm looking forward to the challenge ahead. I know a few of the players and spoke to the goalkeeper coach and he said it's a good club to come to.
"There's a good goalkeeper here as No 1 at the moment who I can learn from, and hopefully everything will go well whilst I'm here. My career just started this season with Cheltenham.
"I need to impress the manager and try to break into the team.'"