# DecryptNode for non-leaf Node in CP-ABE

I've looked at paper Ciphertext-Policy Attribute-Based Encryption by Bethencourt, Sahai, Waters and see this an answer here for the explanation of DecrypNode for a leaf node.

I could understand the derivation of this $$f_n$$ for a leaf node but not for a non-leaf node in the $$s$$.

I could not understand to move from step 2 to 3 and from step 4 to 5.

I will be very grateful if someone can kindly explain the same.

Thanks and Regards

• Welcome to Cryptography. Your question is not clear. Could you post a link? – kelalaka Jan 12 at 20:17
• I have reworded the question. Please see if it is ok now? – user60588 Jan 13 at 9:14
• I've reworded some part of your question. Check that everything is ok. I'll delete this comment. – kelalaka Jan 13 at 9:40