In outsourced database, it is desirable to store sensitive data in an encrypted form to reduce security and privacy risks because the server may not be fully trusted. Several approaches have been proposed in recent literatures to efficiently support queries on encrypted databases. Most researches focus on keywords search and range query while few works study on join query because of a lack of related cryptography primitives. We propose a solution of a privacy-preserving general join supporting both equality tests and simple non-equality tests on ciphertexts by using the revised Boneh–Goh–Nissim encryption algorithm and a Bloom filter. Finally, we analyze its advantages and disadvantages by the comparison with existing method on the performance and the newly introduced security notions. Copyright © 2013 John Wiley & Sons, Ltd.