Maxine Carr, the former girlfriend of Soham murderer Ian Huntley, has been granted an indefinite order protecting her new identity by the High Court.
Maxine Carr has been given a new identity for her protection
She was freed from jail and given a new identity in May, after serving 21 months for lying for Huntley.
Last year the High Court granted a temporary order, saying her identity and whereabouts should be kept secret for her safety.
The new order, granted by Mr Justice Eady, was not contested by the media.
Mr Eady said it was necessary to protect "life and limb" as well as Carr's psychological health.
The order bans publication of any details which could reveal her new identity, including any description of where she lives or the nature of her work.
Earlier, Carr's lawyer Edward Fitzgerald QC argued such an order was justified on the grounds laid down in the previous cases of child killers Jon Venables and Robert Thompson and Mary Bell, where similar permanent injunctions were granted.
He said: "There is a real and significant risk of injury or of worse - killing - if this injunction is not granted."
The 27-year-old former classroom assistant was convicted in December 2003 of conspiring to pervert the course of justice with Huntley, who killed schoolgirls Holly Wells and Jessica Chapman in August 2002.
Carr had given Huntley a false alibi by lying about her whereabouts on the weekend when the two 10-year-olds were killed.