Comments on “Certificateless Short Aggregate Signature Scheme for Mobile Devices”

In the above paper “Certificateless Short Aggregate Signature Scheme for Mobile Devices” a pairing-based certificateless aggregate signature (CLAS) scheme was proposed. Although the authors claim that their CLAS scheme is secure and provide mathematical proof to support this, we show that anyone can create an aggregate signature on any set of messages without the participation of other users.