Crossword Cybersecurity has appointed Sir Richard Dearlove as non-executive chairman.
He succeeds Tom Ilube, who continues in his role of CEO.
Sir Richard's appointment will be effective from 1 September.
Crossword says Sir Richard brings to the board unparalleled experience across government, education and global business. He joined MI6 in 1966 undertaking various overseas and head office roles before being promoted to Chief of the Secret Intelligence Service in 1999. He retired from the Service in 2004. He is presently chairman of trustees of University of London.