Method for cloud storage of data and system

The invention is applicable in the field of computer technology, and provides a method for cloud storage of data and a system. The method and the system comprise the steps of receiving ciphertext data sent by a client and segmenting the ciphertext data into a preset number of ciphertext data fragmentation through a preset first data redundancy segmentation algorithm; receiving a secret key for the ciphertext data which is sent by the client through a preset communication channel, and segmenting the secret key into a preset number of secret key data fragmentation through a preset second data redundancy segmentation algorithm; attaching the preset number of secret key data fragmentation correspondingly to the preset number of ciphertext data fragmentation; storing the preset number of composite data fragmentation respectively in the corresponding cloud storage servers. In an embodiment of the invention, the ciphertext data and the encrypted secret key are segmented into data fragmentation through the preset data redundancy segmentation algorithms, users do not need to save the secret keys and recovery of the secret key, and the ciphertext data is successful only with the preset number of data fragmentation, so that the security of the cloud user data and secret keys is improved.