Prosecutor Duncan Atkinson KC told the Old Bailey last year that Arshad’s actions “lost a tool” being developed at GCHQ, risked exposing the identities of 17 GCHQ colleagues, and undermined the trust of partners, which “created a significant risk of damage to national security”.
Rupert Bowers KC, representing Arshad, argued the sentencing judge had made the sentence too high for a first-time offender.
He said Arshad had “noble if misguided” intentions and no “corrupt motive”.
Bowers said: “This is an exceptional case because of the motivations and the intentions.
“Yes, a serious offence has been committed by someone who was reckless, but he has not committed it intentionally to harm national security.”
At the Court of Appeal on Thursday, Lady Justice Cockerill said the judge had given “careful consideration” to Arshad’s “age, immaturity and neurodivergence” and had rightly taken into account the serious harm to national security which could have been caused.