Jul 28, 2017 · 15m · a16z
Raluca Ada Popa
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gold bands on the timeline = statements, start to end. Hover to read, click to jump. CC turns on captions
At the Andreessen Horowitz Academic Roundtable, UC Berkeley professor Raluca Ada Popa presents BlindBox, a breakthrough system that enables deep packet inspection over encrypted HTTPS traffic without sacrificing user privacy. She also highlights the broader technological shift toward computing on encrypted data across enterprise systems like CryptDB and major cloud services.
How this conversation actually went
Every chapter scored 0–10 on four independent dynamics. Hover any point for the reasoning behind the score. How this is scored →
The host as informed peer 0.0 Guest teaching 6.0 Guest disagreement 0.0 The host pushing back 0.0
speaking balance: gold is the host, purple is the guest (3 minute bins)
Sharpest disagreement ▶ 3:10 Critique of standard SSL middleboxes
The guest forcefully critiques current industry practices as an embarrassing and insecure man-in-the-middle attack that destroys SSL security guarantees.
Hardest push from the host ▶ 3:41 Moderator audio/flow checkThe host/moderator merely interjects a brief 'Ok?' to signal following along, representing the only host participation.
Biggest teaching moment ▶ 7:00 Demystifying searchable cryptography trade-offsPopa educates the listener on the core technical dilemma between fast deterministic encryption and secure randomized encryption.
The host holds their own ▶ 10:00 Detailing secure 2-party computation protocolPopa demonstrates deep cryptographic authority when explaining how secure two-party computation resolves the rule-privacy dilemma.
the scores for every segment, with the reasoning behind each
| Chapter | Topic | The host as informed peer | Guest teaching | Guest disagreement | The host pushing back | Why |
|---|---|---|---|---|---|---|
| Background on Deep Packet Inspection | 0 | 6 | 0 | 0 | The guest presents an academic talk explaining Deep Packet Inspection and how current SSL middlebox workarounds rely on insecure man-in-the-middle attacks. The host only offers a brief check-in ('Ok?'), resulting in zero host expertise or pushback. | |
| Introducing the BlindBox Solution | 0 | 6 | 0 | 0 | Popa introduces BlindBox's threat model and security goals, balancing user privacy with middlebox payload inspection. The host remains entirely passive during the monologue. | |
| BlindBox System Design Overview | 0 | 7 | 0 | 0 | Popa educates the audience on searchable encryption, contrasting fast deterministic schemes with secure randomized schemes. She explains how BlindBox achieves both via AES hardware instructions and salt schedules. | |
| Fast Detection Protocol and Handshake | 0 | 7 | 0 | 0 | The guest details how secure two-party computation allows encrypted rule matching during the SSL handshake without exposing keys or rules. Performance metrics comparing BlindBox to Snort are presented. | |
| Broader Vision: Computing on Encrypted Data | 0 | 6 | 0 | 0 | Popa expands the talk to the wider paradigm of computing on encrypted data, highlighting CryptDB, Myler, and commercial adoption by companies like SAP and Microsoft. | |
| Conclusion and Q&A Transition | 0 | 4 | 0 | 0 | Popa concludes her presentation by emphasizing that privacy and functionality can co-exist in modern software systems before opening for Q&A. |
Statements from this episode (17)
Popa: BlindBox inspects encrypted traffic while maintaining user privacy
“So I'm going to tell you about some very recent work on Blindbox, which enables us to inspect traffic that remains encrypted and protect the privacy of the users.”
Popa: Computing on encrypted data will significantly impact industry
“And then I'm going to scope out from this and tell you about a bigger vision that Blindbox is part of, namely Computing on encrypted data, which I think can have a lot of impact to industry and to what people use today.”
Current HTTPS middlebox workarounds rely on man-in-the-middle attacks
“And actually, the solution is very embarrassing and insecure solution. People basically mount a man in the middle attack on SSL.”
Popa: BlindBox is first system enabling DPI on encrypted traffic
“Our system blind box is the first to show that this could be possible, and is the first system that enables DPI middle boxes to inspect traffic without seeing the traffic.”
Popa: Microsecond Network Speeds Severely Limit Usable Cryptography
“Network rates are on the order of microseconds, so not a lot of cryptography remains that could be used in this setting.”
Raluca Ada Popa: BlindBox HTTPS operates without altering core SSL primitives
“What we build in Blindbox is an enhanced version of HTTPS called Blindbox HTTPS. And with Blindbox HTTPS when a user sends a message the user gets the message gets encrypted through SSL as before, so we don't change SSL.”
Popa: BlindBox encryption matches security of randomized and speed of deterministic schemes
“So as part of Blindbox, our first contribution was to construct such a scheme. A scheme that is as secure as randomized schemes, and as fast as deterministic schemes.”
Popa: BlindBox encryption operates at network rates using hardware AES
“And third is that actually it's fast. It can run at network rates, because it only uses AES, and we have AES instructions in hardware.”
BlindBox uses secure two-party computation during SSL handshake for encrypted rule generation
“So for this, we use really cool primitive from the crypto community, namely secure two-party computation, which enables the middle box and the user during the SSL handshake to produce this encryption scheme to get this encryption encrypted value together witho…”
Popa: BlindBox middleboxes learn only matching malicious string locations
“The middle box learns only if a malicious string matches at some location, but it doesn't learn anything else about the other locations.”
Popa: BlindBox equality matching supports watermarks, filtering, and IDS rules
“Only the equality part that I told you about can support already watermarks, checking if exfiltrated documents contain watermarks, and parental filtering, and a bunch of the IDS rules.”
Popa: BlindBox detection speed is competitive with Snort
“So the detection of the middle box is competitive to Snort.”
Popa: BlindBox increases page load time by 15% to 100%
“In terms of the transmission time, we increase it so page load time would become 15% to a hundred percent slower.”
CryptDB achieved 27% overhead compared to MySQL on TPCC benchmark
“So for industry standard benchmarks such as TPCC, CryptDB had an overhead of 27% compared to MySQL.”
Popa: A Boston hospital uses Myler for medical applications
“And actually a hospital in Boston is currently using Myler in one of their medical applications.”
Popa: Computing on encrypted data eliminates the confidentiality-functionality trade-off
“But the bottom line that I want to mention is that computing on encrypted data can be practical for a set of systems that we use today. And it really gives you, at the same time, confidentiality and functionality. So you don't have to choose only one anymore.”