The homomorphic hash algorithm (HHA) is introduced to help on-the-fly verify the vire-less sensor network (WSN) over-the-air programming (OAP) data based on rateless codes. The re-ceiver calculates the hash value of a group of data by homomorphic hash function, and then it com-pares the hash value with the receiving message digest. Because the feedback channel is deliberately removed during the distribution process, the rateless codes are often vulnerable when they face secu-rity issues such as packets contamination or attack. This method prevents contaminating or attack on rateless codes and reduces the potential risks of decoding failure. Compared with the SHA1 and MD5, HHA, which has a much shorter message digest, will deliver more data. The simulation results show that to transmit and verify the same amount of OAP data, HHA method sends 17. 9％ to 23. 1％fewer packets than MD5 and SHA1 under different packet loss rates.