Riven

Steven Mackintosh

as Himself - Narrator

Brian Deacon

as Gordon Welchman (voice)

Rosamund Welchman

as Herself - Gordon Welchman's Daughter

W. Gordon Welchman

as Himself - Ex-Head of Hut 6, Bletchley Park (1939-1941) (archive footage)

Sinclair McKay

as Himself - Author, 'The Secret Life of Bletchley Park'

Jimmy Thirsk

as Himself - Veteran, Hut 6

Asa Briggs

as Himself - Veteran, Hut 6

Jane Fawcett

as Herself - Veteran, Hut 6

Tony Comer

as Himself - GCHQ Historian and Former Analyst

John Naughton

as Himself - Vice President, Wolfson College, Cambridge (as Prof John Naughton)

John Scarlett

as Himself - Chairman, Bletchley Park Trust, and Former Chief, MI6 (as Sir John Scarlett KCMG OBE)

Jennifer Welchman

as Herself - Gordon Welchman's Granddaughter

Robert R. Everett

as Himself - Former President, The MITRE Corporation

Eric Ellingson

as Himself - Gordon Welchman's Colleague

Larry Hill

as Himself - Gordon Welchman's Colleague

Russell England

Director

John Smithson

Director