Lin Ding presented improved related cipher attack (IRCA) on 256-bit key Salsa20, by considering same secret key with two separate IVs used in Salsa20/12 and Salsa20/8 and recovered secret key with time complexity 2 193.58. Presented an algorithm to find unknown key words based on exhaustive search for 256-bit Salsa20. In this paper, similar to Lin Ding, IRCA on 128- bit key Salsa20 is applied by considering same secret key with one IV used in Salsa20/12 and Salsa20/10 and recovered secret key with time complexity 2 96. To achieve this, one forward round from (R10(m)) to (R11(m)) and one reverse round from (R12(m))-1 to (R11(m))-1 is applied. The same idea is utilized to find the unknown key words based on exhaustive search for 128-bit key Salsa20. Similarly, IRCA on 256-bit key ChaCha is applied by considering same secret key with two separate IVs used in ChaCha4 and ChaCha8 and secret key is recovered with time complexity 2 225. To achieve this, two forward round from (R4(m)) to (R6(m)) and two reverse round from (R8(m))-1 to (R6(m))-1 is applied. The same idea is utilized to find the unknown key words based on exhaustive search for 256-bit key ChaCha.