Title
CoKey: fast token-based cooperative cryptography.
Abstract
Keys for symmetric cryptography are usually stored in RAM and therefore susceptible to various attacks, ranging from simple buffer overflows to leaks via cold boot, DMA or side channels. A common approach to mitigate such attacks is to move the keys to an external cryptographic token. For low-throughput applications like asymmetric signature generation, the performance of these tokens is sufficient. For symmetric, data-intensive use cases, like disk encryption on behalf of the host, the connecting interface to the token often is a serious bottleneck. In order to overcome this problem, we present CoKey, a novel concept for partially moving symmetric cryptography out of the host into a trusted detachable token. CoKey combines keys from both entities and securely encrypts initialization vectors on the token which are then used in the cryptographic operations on the host. This forces host and token to cooperate during the whole encryption and decryption process. Our concept strongly and efficiently binds encrypted data on the host to the specific token used for their encryption, while still allowing for fast operation. We implemented the concept using Linux hosts and the USB armory, a USB thumb drive sized ARM computer, as detachable crypto token. Our detailed performance evaluation shows that our prototype is easily fast enough even for data-intensive and performance-critical use cases like full disk encryption, thus effectively improving security for symmetric cryptography in a usable way.
Year
DOI
Venue
2016
10.1145/2991079.2991117
Annual Computer Security Applications Conference
Keywords
Field
DocType
Cooperative Cryptography, Cryptographic Token, USE Token, Data Confidentiality, Full Disk Encryption, USB Armory
Symmetric-key algorithm,Token passing,Disk encryption,Computer security,Computer science,Token ring,Computer network,Encryption,Software token,Security token,Token bus network
Conference
ISSN
Citations 
PageRank 
1063-9527
0
0.34
References 
Authors
20
3
Name
Order
Citations
PageRank
Julian Horsch1184.58
Sascha Wessel2237.24
Claudia Eckert37613.13