Surnaming schemes, fast verification, and applications to SGX technology

We introduce a new cryptographic primitive that we call surnaming, which is closely related to digital signatures, but has different syntax and security requirements. While surnaming can be constructed from a digital signature, we show that a direct construction can be somewhat simpler. We explain how surnaming plays a central role in Intel’s new Software Guard Extensions (SGX) technology, and present its specific surnaming implementation as a special case. These results explain why SGX does not require a PKI or pinned keys for authorizing enclaves. SGX motivates an interesting question in digital signature design: for reasons explained in the paper, it requires a digital signature scheme where verification must be as fast as possible, the public key must be short, but signature size is less important. We review the RSA-based method currently used in SGX and evaluate its performance. Finally, we propose a new hash-based signature scheme where verification time is much faster than the RSA scheme used in SGX. Our scheme can be scaled to provide post-quantum security, thus offering a viable alternative to the current SGX surnaming system, for a time when post-quantum security becomes necessary.