par 1: 'Before exTNFS' -> 'Before the exTNFS attacks'; 'BN curves with 256-bit size of underlying finite field' -> 'BN curves defined over 256-bit finite fields'; 'the security level of BN curves with 256-bit size of underlying finite field' -> 'the security level of BN256 curves'; 'fell into' -> 'fell to'
par 2: 'who will newly develop the' -> 'who are currently developing the' or 'who will develop new'
par 3: 'There exists applications which already implemented' -> 'There exist applications which intentionally use'; 'In such a case' -> 'In such cases'
Comments from Chloe (Expert Reviewer)