question: public static RevocationHash bruteForceHash ( byte [ ] seed , byte [ ] target , int maxChildTries , int maxSiblingTries ) { for ( int i = 0 ; i < maxChildTries ; i ++ ) { for ( int j = 0 ; j < maxSiblingTries ; j ++ ) { RevocationHash test = HashDerivation . calculateRevocationHash ( seed , 0 , j ) ; if ( Arrays . equals ( test . getSecretHash ( ) , target ) ) { return new RevocationHash ( i , j , test . getSecret ( ) , test . getSecretHash ( ) ) ; } } seed = Tools . hashSecret ( seed ) ; } return null ; }
target:  The other party has breached the contract and submitted an old channel transaction.