Do you mean ACID compliance in NoSQL? Please take a look at rather old (but still up to date) post on Stack Overflow: http://stackoverflow.com/questions/2608103/is-there-any-nosql-that-is-acid-compliant
Have a look at http://nosql-database.org/ for a very good round up of nosql databases. Do you mean to ask if they are secure or are they ACID compliant. Also nosql is not a technology in itself. It is an umbrella term to cover a number of different ways of storing different types of data.