CCSDS Security WG -

ESA UNCLASSIFIED
–

For Official Use

CCSDS Security WG
-


I. Aguilar, D. Fischer

CCSDS Fall 2012 Meeting, Cleveland, USA

15/10/2012

ESA Presentation | I. Aguilar, D. Fischer | CCSDS Fall 2012 Meeting, Cleveland, USA | 15/10/2012 | TEC | Slide
2

ESA UNCLASSIFIED
–

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Motivation


The objective of this presentation is to share information concerning
recent ESA activities and participation to conferences and workshops
which is deemed relevant to the CCSDS Security Working Group.

•
Information.

•
Discussion of possible new areas for work.

ESA Presentation | I. Aguilar, D. Fischer | CCSDS Fall 2012 Meeting, Cleveland, USA | 15/10/2012 | TEC | Slide
3

ESA UNCLASSIFIED
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Topics


Physical
Layer Security (IAS
).


Ongoing
Key Management Research at ESA
-
University of Waterloo
(IAS/DF
).


Directions
in Authenticated Ciphers (DIAC 2012 Workshop)
-

Debriefing
(IAS/DF
).


ESTEL
2012 Conference
-

Debriefing (IAS
).


SpaceOps

2012 Conference
–

Debriefing (DF).





ESA Presentation | I. Aguilar, D. Fischer | CCSDS Fall 2012 Meeting, Cleveland, USA | 15/10/2012 | TEC | Slide
4

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Physical Layer Security

Cryptographic spread spectrum (1)


As part of a general effort to strengthen TT&C links against denial
-
of
-
service attacks (jamming), ESA initiated research on two specific
topics:

•
Cryptographic sequences to be applied on spread spectrum
communications with multiple
-
user access capability and

•
Advanced synchronization techniques able to acquire such
ultra
-
long codes under signal dynamic conditions (Doppler,
jerk) experienced by various missions topologies as well as
under stress (jamming).


Such research was funded with an activity of the ESA Technology
Research Programme (TRP). Thales
Alenia

Space (Italy), a leading
European supplier of ‘robust’ transponders, teamed up with Prof. J.
Massey, a well
-
known authority on both pseudo
-
noise sequences and
cryptography.


ESA Presentation | I. Aguilar, D. Fischer | CCSDS Fall 2012 Meeting, Cleveland, USA | 15/10/2012 | TEC | Slide
5

ESA UNCLASSIFIED
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Physical Layer Security

Cryptographic spread spectrum (2)


The research effort delivered good results. A family of pseudo
-
noise
sequences that can provide both cryptographic strength and controlled
cross
-
correlation, vital for multi
-
user access was identified.


Cryptographic Pseudo
-
Noise Sequences:

•
Let

PN
CR

be

the

cryptographically

strong


1

PN

sequence

that

is

assigned

to

every

satellite
.

•
Let

PN
MA
(i)

be

the

periodic


1

PN

spreading

sequence

whose

first

period

corresponds

to

the

phase

of

the

maximal
-
length

sequence

that

is

assigned

to

the

i
th

satellite
.

•
Spreading

sequence

PN
(i)

used

by

the

G/S

for

transmission

to

the

i
th

satellite

is

the

Hadamard

produc
t

of

PN
CR

and

PN
MA
(
i
)
,

i
.
e
.
,


PN
(
i
)

=
PN
CR

PN
MA
(
i
)
.



ESA Presentation | I. Aguilar, D. Fischer | CCSDS Fall 2012 Meeting, Cleveland, USA | 15/10/2012 | TEC | Slide
6

ESA UNCLASSIFIED
–

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Physical Layer Security

Cryptographic spread spectrum (3)


Furthermore, techniques to quickly synchronize very long PN
sequences were identified, analysed and evaluated.

•
Those
techniques, based on frequency
-
domain signal
processing
algorithms (Generalized Zero Padding),
have
improved several orders of magnitude the performance
compared with classical serial search techniques.

•
In
combination with a clever 3
-
step acquisition protocol, they
allow to transit from an already long PN sequence (2exp 22) to
a cryptographic sequence in a few seconds.


Some details of the acquisition technique can be found on the following
paper presented at MILCOM 2011
.

•
Fast acquisition techniques for very long PN codes for On
-
Board Secure TTC transponders
,
L
. Simone
,
G.Fittipaldi
, I.
Aguilar Sánchez.




ESA Presentation | I. Aguilar, D. Fischer | CCSDS Fall 2012 Meeting, Cleveland, USA | 15/10/2012 | TEC | Slide
7

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Physical Layer Security

Advanced TC Coding (1)


CCSDS
Telecommand

Space

Link Protocol employs BCH code either in TED
(triple error detection) or SED (single error correction) modes.

•
High integrity;

•
Somewhat limited coding gain;

•
Average White Gaussian Noise (AWGN) channel.


Such BCH codes are sub
-
optimal for spread spectrum modulations.

•
Poor performance under jamming, which produces burst errors.


Enhancement for cryptographic direct
-
sequence spread
-
spectrum
modulation highly desirable.

•
Potential to increase robustness under interference/jamming.


Concatenation of convolutional (r=1/2, K=7) existing for a while in systems
like TDRSS and used in missions like ATV

•
Improvement under AWGN condition;

•
Still too sensitive to burst errors.

ESA Presentation | I. Aguilar, D. Fischer | CCSDS Fall 2012 Meeting, Cleveland, USA | 15/10/2012 | TEC | Slide
8

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Physical Layer Security

Advanced TC Coding (2)


Can better codes be found to complement cryptographic direct
-
sequence
spread
-
spectrum modulation?

•
Consider the particular requirements of TC protocol like the ability
to encode from short (64 octets) to relatively large (1024 octets)
blocks of data;

•
Consider most destructive jamming signals for direct
-
sequence
modulation (e.g. pulsed jammer);

•
Consider coding literature;

•
Consider relevant CCSDS experience.


A study with
Politecnico

di Torino (Italy) and Univ.
Politecnica

delle

Marche
(Italy) just initiated in September 2012.

•
Team has very strong record both on coding and CCSDS;

•
Targets mainly Binary Low Density Parity Check Codes (LDPC);

•
Considers as well NASA LDPC codes proposed for TC (in AWGN
condition) but under jamming environment.

ESA Presentation | I. Aguilar, D. Fischer | CCSDS Fall 2012 Meeting, Cleveland, USA | 15/10/2012 | TEC | Slide
9

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Physical Layer Security

Secret channels


C. Shannon
, the father of Information Theory, among other key works established the
foundations of secret channel capacity;


A.D.
Wyner

builds on previous Shannon work on secret channels and produces another
seminal paper

•
The Wire
-
Tap Channel
, Bell System Technical Journal, 1975.

Source
Encoder
Main Channel
Decoder
Wiretap
Channel
S
k
X
k

Y
n
S
k
Z
n

ESA Presentation | I. Aguilar, D. Fischer | CCSDS Fall 2012 Meeting, Cleveland, USA | 15/10/2012 | TEC | Slide
10

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Physical Layer Security

Why bother?


The design of proper ‘channel codes’ can increase the Rate of
Equivocation (term defined by Shannon) of the eavesdropper;


In theory, no need for data encryption with such codes on a wireless
channel!

•
Unbreakable, regardless of attacker’s computing power;

•
Mobile communications research community is very actively
working on this subject;

•
Authentication also possible;


The cryptographers contender to quantum encryption, working on RF!


In the absence of my personal database on this topic (
hard disk with all
my files undergoing encryption at ESTEC!)

present some slides from
Vince Poor (Princeton) covering the topic.

•
http://
wireless.vt.edu/symposium/2012/keynote/poor.html


ESA Presentation | I. Aguilar, D. Fischer | CCSDS Fall 2012 Meeting, Cleveland, USA | 15/10/2012 | TEC | Slide
11

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On
-
going Key Management Research

ESA NPI (1)


ESA and the University of Waterloo (Canada) are working together on
key management research for space missions under the ESA Network
Partnering Initiative (NPI).

•
Each partner funds 50% of the research.

•
Research can be for a Ph.D. or post
-
doc.


Dr.

Marcio

Juliato

(Univ. of Waterloo) is the lead researcher.


Project Co
-
supervisors:

•
Prof. Catherine H.
Gebotys

(Univ. of Waterloo);

•
I. Aguilar Sánchez (ESA/ESTEC).


Project Details:

•
Schedule:

–
3
-
years, initiated summer 2011,

–
o
f which 1
-
year stay at ESTEC with visits to ESOC.

ESA Presentation | I. Aguilar, D. Fischer | CCSDS Fall 2012 Meeting, Cleveland, USA | 15/10/2012 | TEC | Slide
12

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On
-
going Key Management Research

ESA NPI (2)

•
3 Phases:

–
Phase 1, focusing on providing scientific basis for the determination of
crypto periods for TC and TM secure communications links on space
missions based on symmetric algorithms; 2 generic missions considered
with GEO and LEO orbits;

–
Phase 2, looking at the use of trusted modules for key
management/recovery;

–
Phase 3, investigating more complex mission topologies like those relying
on space networks and the application of asymmetric algorithms to support
key management.


Results of first phase:

•
Draft Technical Report produced;

•
Paper recently presented at IEEE AESS ESTEL 2012 Conference.

–
On the Specification of Symmetric Key Management Parameters for Secure
Space Missions
,
Marcio

Juliato

, Catherine
Gebotys
,
Ignacio Aguilar
Sanchez.







ESA Presentation | I. Aguilar, D. Fischer | CCSDS Fall 2012 Meeting, Cleveland, USA | 15/10/2012 | TEC | Slide
13

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Directions in Authenticated Ciphers
(DIAC 2012 Workshop)
(1)


This workshop is part of ECRYPT, the European Network of Excellence in
Cryptology; this is a network funded by the European Commission Seventh
Framework Programme.


This workshop gathered top cryptographers and practitioners in industry
and academia like

•
B.
Preneel
, Univ.
Katoliek

Leuven (Belgium);

•
P.
Rogaway
, Univ. of California at Davis, USA;

•
J.
Daemen
, STM Microelectronics, AES
father
;

•
A, McGrew
, CISCO, USA (AES
-
GCM
father
);


The following website provides relevant information:

•
http://hyperelliptic.org/DIAC
/


ESA presented a
‘white paper’
with a view to inform the research community
and possibly trigger their interest about the particular requirements, issues,
constraints and concerns of authenticated encryption:

•
Authenticated encryption in civilian space missions: context and
requirements
, I. Aguilar Sánchez, D. Fischer


ESA Presentation | I. Aguilar, D. Fischer | CCSDS Fall 2012 Meeting, Cleveland, USA | 15/10/2012 | TEC | Slide
14

ESA UNCLASSIFIED
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Directions in Authenticated Ciphers
(DIAC 2012 Workshop)
(2)


Feedback:

•
Space considered a user community at one (tough) end of the
spectrum of user requirements (
T. Lange
dixit);

•
At opposite end one can find the so
-
called
‘lightweight
cryptography’
(e.g. embedded processors);

•
Some surprise shown by the anticipated need for a MAC longer
than 128 bits (
D. McGrew
);

•
D
oubt raised about the true security strength given by a particular
MAC length, triggered by conversation with
P.
Rogaway
;
apparently a 128
-
bit MAC would give 128
-
bit security (not 64
-
bit);
question still to be solved!

•
NIST and some top non
-
European Universities (USA, Japan)
actively involved in the Workshop;

•
Possibly a new competition for an advanced AE algorithm in the
pipeline; certainly, a lot of interest by represented parties;
however, who would fund it?

ESA Presentation | I. Aguilar, D. Fischer | CCSDS Fall 2012 Meeting, Cleveland, USA | 15/10/2012 | TEC | Slide
15

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ESTEL 2012 Conference


See
http://www.estelconference.org/


Organised by IEEE Aerospace and Electronic Systems Society in Europe (a
first!);

•
Broad scope: satellites, launchers, navigation, earth observation,
ground systems, satellite networks,…


A
Special Track on Security and Privacy
…

•
Covering a broad range of security issues, well beyond space
missions.


But a good
Security Session

in general program with papers like

•
Marcio’s

paper on Key Management;

•
Cryptographic Transforms for a Lightweight and Efficient DVB Link
-
Layer Security
Extension
, Michael
Nosterning
, University of
Salzburg;

•
Ignacio’s paper on Telecommunication Mission Security, including
PR campaign for CCSDS Security!