Assalamu alaykum,my friend told me a secret (though it was not hers) just about one thing and told me not to tell anyone,though it's not something big that needs to be kept as a secret and additionally she said it is an AMANAH,1.Is it permissible for a person to say amanah for sharing secrets2.If revealed it to someone but then repented to Allah,does that person have to tell that person that she revealed her secrets and ask forgiveness?

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His Slave and Messenger.

There is no harm in using the word 'amanah' as a reminder to keep a matter confidential and not disclose it, for secrets are a trust. The prohibition of disclosing a secret becomes even more emphatic if the person explicitly requested that it be kept confidential, or if there is fear that harm may result from revealing it.

Accordingly, it is not permissible for you to disclose this secret, even if you consider it something ordinary or not directly related to her. What matters is that she entrusted you with it and asked you to keep it confidential. Moreover, she is more aware of the potential consequences, and harm may result to her or to her friend if it is disclosed.

If a violation occurs and the secret is disclosed, then sincere repentance with its required conditions is obligatory. You are not required to inform your friend that you disclosed her secret, because seeking absolution in such intangible matters often leads to greater harm. For this reason, some scholars have stated that seeking direct pardon is not required in such cases; rather, it is sufficient to supplicate and seek forgiveness on her behalf.

Allah Knows best.