Crossword Genius

Secure chat may not be reliable (8)

Ross

I believe the answer is:

fasttalk

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'not be reliable' is the definition.
I don't know anything about this answer so I cannot tell whether this works.

'secure chat' is the wordplay.
'secure' becomes 'fast' (fast can mean secure or fixed).
'chat' becomes 'talk' (I've seen this in another clue).
'fast'+'talk'='FASTTALK'

'may' acts as a link.

Can you help me to learn more?

I've seen this clue in The Irish Times.
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