Secure digital traffic analysis
A network monitoring “sensor” is built on initial startup by checking the integrity of the bootstrap system and, if it passes, downloading information from which it builds the full system including an encrypted and an unencrypted portion. Later, the sensor sends hashes of files, configurations, and other local information to a data center, which compares the hashes to hashes of known-good versions. If they match, the data center returns information (e.g., a key) that the sensor can use to access the encrypted storage. If they don't, the data center returns information to help remediate the problem, a command to restore some or all of the sensor's programming and data, or a command to wipe the encrypted storage. The encrypted storage stores algorithms and other data for processing information captured from a network, plus the captured/processed data itself.
1. A base system for a data network monitoring system, the base system comprising a processor, a network interface, and a memory, the memory being encoded with data and programming that is executable by the processor to:
provide an operating system for the base system;
retrieve build information from a secure source via the network interface;
use the build information to set up operational components, the operational components comprising:
validity check programming;
encrypted storage access control programming; and
error-handling programming;
as the data network monitoring system starts up, execute the validity check programming to determine the security state and identity of the base system or data network monitoring system;
when the validity check programming reveals a correct state and identity, then allowing the data network monitoring system to complete a startup process and perform its intended use by:
using the encrypted storage access control programming, accessing a first portion of the memory as encrypted storage, leaving a second portion of the memory as unencrypted storage; and
capturing data at the network interface and processing the captured data as a function of information in the encrypted storage; and
when the validity check programming reveals an incorrect security state or identity, executing the error-handling programming.
2. The system of claim 1 , wherein the encrypted storage contains information usable by the processor to implement one or more algorithms for processing data captured at the network interface.
3. The system of claim 1 , wherein the encrypted storage contains at least a portion of the data captured at the network interface.
4. The system of claim 1 , wherein the encrypted storage contains information usable by the processor to implement one or more functions that are not implemented in programming stored in the unencrypted storage.
5. The system of claim 1 , wherein programming stored in the unencrypted storage is executable by the processor at boot time to:
initially avoid accessing the encrypted storage;
communicate with a remote computer via the network interface;
receive unlocking instructions from the remote computer; and
use the unlocking instructions to access the encrypted storage.
6. The system of claim 5 , wherein the unlocking instructions comprise information including key material usable for decrypting the encrypted storage.
7. The system of claim 5 , wherein the communicating with the remote computer comprises sending one or more hashes of information stored in the unencrypted storage to the remote computer for validation.
8. The system of claim 7 , wherein the hashes include hashes of three or more source items selected from the source item collection consisting of:
files in the unencrypted storage,
one or more user accounts,
local passwords,
listings of directories in the unencrypted storage,
a software manifest, and
configuration options for one or more software subsystems.
9. The system of claim 5 , wherein the programming stored in the unencrypted storage is further executable by the processor to
determine whether the unencrypted storage is in a secure state; and
if the unencrypted storage is not in a valid state, put the unencrypted storage into a secure state.
10. The system of claim 1 , wherein processing the captured data comprises storing at least a portion of the captured data in the encrypted storage.