ID-based broadcast encryption scheme containing customized information

Abstract

The invention discloses an ID-based broadcast encryption scheme containing customized information, which belongs to the communication safety field. The scheme comprises the following steps that safety parameters are initialized; a broadcast center creates a set U of n users, ID spaces and generates a public key params, a main secret key msk and further makes the params public through a broadcast channel. The broadcast center acquires the ID information of a user Ui (Ui is one in the user set U) and generates a private key ski which is sent to the Ui. The broadcast center calculates a broadcast secret key K, the customized secret key K'i of Ui and a broadcast head Hdr. A symmetric encryption algorithm is used to encrypt broadcast information m (the secret key being K) to acquire c. The customized information m'i (the secret key being K'i) is encrypted to acquire c'i. (Hdr, c, c'i (i being within {1, ....,n}) are made public through the broadcast channel. Only users in the broadcast set U can perform the following steps of recovering the secret keys K and K'i from the Hdr through the private key; using k to decrypt c and acquire broadcast information; and using K'i to decrypt c'i and acquire customized information. The scheme is suitably used in broadcast systems containing customized information, for example, a condition receiving system. Meanwhile, customized information, security and collusion attack preventing services are provided for information transmission in the broadcast set.

Description

Technical field [0001] The invention relates to cryptography, belonging to the field of communication security, and in particular to an identity-based broadcast encryption scheme with personalized information. Background technique [0002] Broadcast encryption provides a way to securely transmit the same message to multiple different users at the same time on an insecure channel. It has a wide range of applications in the fields of digital pay TV, satellite communications, teleconferences, and FM radio. It was first proposed by Berkovits in the article "Howtobroadcastasecret" in 1991, and was later established as a new research field of cryptography in the article "broadcast encryption" in 1993 by AmosFiat and MoniNaor. [0003] The broadcast encryption system is divided into two types: symmetric broadcast encryption system and public key broadcast encryption system. The difference lies in whether the encryption party and decryption party use the same session key. The symmetric br...

AI Technical Summary

Problems solved by technology

However, none of the above solutions can satisfy the transmission of personalized messages for a certain user while transmitting broadcast information.

[0006] In 2010, Ohtake and other scholars combined the BGW scheme with the Kurosawa scheme and proposed the first broadcast encryption scheme with personalized information. This scheme is based on bilinear mapping, but the length of the public key is very large, which increases linearly with the number of users.

Therefore, there is no scheme that can more efficiently combine the broadcast encryption system and the multi-receiver encryption system to produce an identity-based broadcast encryption scheme with personalized information with a short public key length.

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