The Blob: provable incompressibility and traceability in the whitebox model
This addresses software security and piracy prevention for industries like pay-TV, but appears incremental as it builds on existing whitebox models with specific variants.
The paper tackles the problem of securely distributing and storing software with cryptographic functionality in the whitebox attacker model by introducing a scheme based on a large random data blob for incompressibility and traceability, showing that it is feasible for applications like pay-TV with analysis of decryption limits under collusion attacks.
We introduce a scheme for distributing and storing software with cryptographic functionality in the whitebox attacker model. Our scheme satisfies two relevant properties: incompressibility and traceability. The main idea is to store a large amount of random data (a `blob'), some of which will be randomly sampled in the future to serve as key material, and some of which serves as a watermark. We study two variants: with and without re-use of key material. For both variants we analyse how many decryptions can be performed with the blob, taking into account collusion attacks against the watermark. Our results show that application of blob schemes in the context of pay-TV is feasible.