Murphy was instrumental in Scunthorpe's title win last season

The 25-year-old, who kept 24 clean sheets last season as the Iron won the League One title, only had one year remaining on his current deal.

"It's great to sign, and I'm looking forward to the start of the season," he told Scunthorpe's website.

Murphy, who began his career at Tranmere, joined the Iron last summer from Sunderland and has also played for West Bromwich Albion and Walsall.