[Busec] BUsec this week: Dana Dachman-Soled (Tues 11AM)

Sharon Goldberg goldbe at cs.bu.edu
Tue Mar 27 09:55:29 EDT 2012

Hi all,

A reminder for Dana's talk today 11AM in MCS148 at 111 Cummington St.
Abstract below.  Talk is open to the public and lunch will be provided
around noon.

Also, for those that have not seen this yet, Scott Aaronson is giving
a talk in the Math Department at BU on Friday at 4PM.  Scott is always
an entertaining speaker:  http://math.bu.edu/mifc/

Finally, I just found about about an network security talk in ECE,
that may be of interest to some. Friday at 10AM, abstract pasted


BUsec mailing list:  http://cs-mailman.bu.edu/mailman/listinfo/busec

Securing Circuits Against Constant-Rate Tampering
Dana Dachman-Soled. MSR.

We present a compiler that converts any circuit into one that remains
secure even if a constant fraction of its wires are tampered with.
Following the seminal work of Ishai et. al. (Eurocrypt 2006), we
consider adversaries who may choose an arbitrary set of wires to
corrupt, and may set each such wire to 0 or to 1, or may toggle with
the wire. We prove that such adversaries, who continuously tamper with
the circuit, can learn at most logarithmically many bits of secret
information (in addition to black-box access to the circuit). Our
results are information theoretic, and do not rely on any tamper-proof

Joint work with Yael Kalai.

---------- Forwarded message ----------
From: Ari Trachtenberg <trachten at bu.edu>

Main Speaker: Yossi Gilad, Bar Ilan University
Location: Rm 404/428, Photonics Building
Time: Friday 10AM.

Title: Fragmentation Considered Vulnerable

We show that fragmented IPv4 and IPv6 traffic is vulnerable to
effective DoS, interception and modification attacks by an off-path
attacker. Specifically, we demonstrate a weak attacker causing over
94% loss rate and intercepting more than 80% of the data between

We show that our attacks are practical through experimental validation
on popular industrial and open-source products, with realistic network
setups (involving NAT or tunneling),
including concurrent legitimate traffic and packet losses. The
interception attack requires a zombie
behind the same NAT or tunnel-gateway as the victim destination; the
other attacks only require a puppet (adversarial applet/script in
sandbox). The complexity of our attacks depends on the predictability
of the IP Identification (ID) field. The attacks are much simpler and
more efficient for implementations, such as Windows, which use
globally incrementing IDs. However, we also present effective attacks
for implementations, such as Linux, which use
per-destination-incrementing IDs.

We present practical defenses for the attacks presented in this paper,
the defenses can be deployed on network firewalls without changes to
hosts or operating system kernel.

This is joint work with Professor Amir Herzberg (Bar Ilan University).
It was presented at the USENIX Workshop on Offensive Technologies; a
full version of it is now in submission to ACM TISSEC journal.

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