The invention relates to a data processing device and a transaction system, the data processing equipment is coupled with a data acquisition device and comprises a data collection device, an encryption chip, a data processing device and a transmission device, and the data collection device is used for collecting data acquired by the data acquisition device and transmitting the data to the encryption chip; an Encryption chip, generating a public and private key pair of the first user, encrypting the collected data by adopting the public key of the first user to generate ciphertext data, transmitting the ciphertext data to the data processing device, receiving a public key of a second user from the data processing device, generating a re-encryption key by adopting the private key of the first user and the public key of the second user, and transmitting the re-encryption key to the data processing device; The data processing device receives the public key, transmitted by the transmissiondevice, of the second user, transmits the public key to the encryption chip, receives the ciphertext data and the re-encryption key and transmits the ciphertext data and the re-encryption key to the transmission device; And the transmission device is used for transmitting the ciphertext data and the re-encrypted data to a network side. By adopting the scheme, the security of data flow can be improved.