Top of the list was 123456, appearing in more than 23 million passwords. The second-most popular string, 123456789, was not much harder to crack, while others in the top five included "qwerty",* "password" and 1111111.
The most common name to be used in passwords was Ashley, followed by Michael, Daniel, Jessica and Charlie.
When it comes to Premier League football teams in guessable passwords, Liverpool are champions and Chelsea are second. Blink-182 topped the charts of music acts.
People who use well-known words or names for a password put themselves people at risk of being hacked, said Dr Ian Levy, technical director of the NCSC.
"Nobody should protect sensitive data with something that can be guessed, like their first name, local football team or favourite band," he said.
*QWERTY – symboliczna nazwa układu liter do alfabetu łacińskiego na klawiaturze maszyny do pisania i komputera, zaczerpnięta od pierwszych sześciu liter w szeregu pod rzędem cyfr, patrząc od lewej. W pierwszych maszynach do pisania stosowano alfabetyczne ustawienie klawiszy.
