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AES-256 RSM (v4)

AES-128 RSM (v4.2)



Frequently Asked Questions


DPA Contest v4.2 Reference Traces


A reference acquisition campaign has been performed during July and August 2014 in the security laboratory the Digital Electronic Systems research group of the Télécom ParisTech french University. The algorithm was implemented on an ATMega-163 smart-card connected to a SASEBO-W board.

This reference acquisition campaign contains 80,000 traces. We used 16 different keys and for each key, we collected 5,000 traces corresponding to the encryption of 5,000 different plaintexts per key.


To test your attack, you will need to download both the index file and some traces (you do not have to download all the traces).

Index file

The index file contains the key, plaintexts, ciphertexts and other information used for each traces.


To allow participants not to download the full set of traces, the campaign is divided into 16 subsets of 5,000 traces each (each subset contains the traces corresponding to 1 key). Each subset is a 3.9 GBytes ZIP archive.

Important update (August 27, 2015): During the life of the v4.2 contest, two bugs have been identified in the implementation used to perform the acquisitions. Both bugs concern Suffle0 and Shuffle10 permutations. The first one has been discovered on October 2014 and the second one has been discovered on August 2015.

The traces available below has been updated on July 2015 and does not contain the first bug but does contain the second one. Please consult the page Documentation for more details on this bug.

You can check the integrity of the files after download with these SHA1sums:

f711206b413b8d02f595d5861996ff61a1711f3d  DPA_contestv4_2_k00.zip
558020ee66c9948be8e08ea41e9fb7389d3f9db3  DPA_contestv4_2_k01.zip
1f1c539b9a2461994a126240b6cc8cf51193b4e5  DPA_contestv4_2_k02.zip
958827acf7dc9740715fe2d76f80d3f5e2e5237e  DPA_contestv4_2_k03.zip
74f3e7dbdaa9fe18660f6fbf462423a758e998bf  DPA_contestv4_2_k04.zip
5535342a4131d2881d23b4781a033efb89a4279f  DPA_contestv4_2_k05.zip
8bc2d9b322319bef4dc32fdce19357b3c2faf109  DPA_contestv4_2_k06.zip
aed1516046a6b6e4a80b3bec2190f7fbf60945e5  DPA_contestv4_2_k07.zip
25ec6a41fbbbca9829d1af51a133e01f46ba2abe  DPA_contestv4_2_k08.zip
1c96aa67e2f26edcd38ad152953c6059a1343bdc  DPA_contestv4_2_k09.zip
82365e174dd6ffb2c61e52154ed73f10b04f800d  DPA_contestv4_2_k10.zip
354d13867bf83d44e53a257e215d58572a4c9088  DPA_contestv4_2_k11.zip
b67e99c4aae59a6603bfd1f8183b15f1f4794d05  DPA_contestv4_2_k12.zip
e04f746fbc3bea19a2940250b10a3715a6964242  DPA_contestv4_2_k13.zip
77a9b52b0b8604a351a6af87812eb6306cfb1dfa  DPA_contestv4_2_k14.zip
1fe1086a8e05044363fc426a58e64bf6df61a658  DPA_contestv4_2_k15.zip
792e966a60898e0b8fcb96f6b52ae42228f14970  dpav4_2_index

Format of the traces and index file

Index file

Each line of the index file contains the information about a trace.


8249CEB658C71D41D7B734449629AB97 73136C16F1E0CE864A2A2C6C8400CF01 BDAA8B4BE13E13CD5250685B67443F84 AB5D4F761C28E039 1A9406F3B2857CED 05C229626F9D8B39 k00 DPACV42_000000.trc.bz2

On each line, the information are separated by a space:


Each trace subset ZIP archive contains 5,000 traces that decompress into a subdirectory of directory DPA_contestv4_2 (in order to allow participants to only download a part of the campaign and to limit the number of files inside the same directory):

| |- DPACV42_000000.trc.bz2
| |- DPACV42_000001.trc.bz2
| |...
| |- DPACV42_005000.trc.bz2
| |- DPACV42_005001.trc.bz2
| |...

In order to limit its size, each file is compressed with bzip2. You can uncompressed them but it is not necessary as the tools we provide can manipulate compressed traces.

Each file DPACV42_xxxxx.trc.bz2 contains a single trace coded using the LeCroy Digital Oscilloscope format template 2.3.

Short version: After the first 357 bytes of the file (headers), there are 1,704,402 bytes which represent the 1,704,402 samples of the trace, the value (between -128 and +127) of each sample is coded on 1 byte (8 bit two's complement, i.e. signed value).

Complete version: The trace header starts with the string WAVEDESC. All the offsets in the table below are relative to the first character of this string. Some bytes (11 in the case of the traces of the DPA contest v4) precede this string and should not be taken into account. The table below describes the important fields of the headers of a trace.

Offset (in byte)
Relative to beginning of
Name Type Description Typical values for provided traces
0 Descriptor Name Null terminated string The first 8 chars are always "WAVEDESC" WAVEDESC
16 Template Name Null terminated string LECROY_2_3
32 Comm Type 16-bit data Format of data samples (0: byte (8-bit signed values), 1: word (16-bit signed values)) 0 (8-bit signed values)
34 Comm Order 16-bit data Format of data samples (0: MSB first, 1: LSB first) 1 (LSB first)
36 Wave Descriptor 32-bit signed data Length in bytes of the block WAVEDESC 346
40 User Text 32-bit signed data Length in bytes of the block USERTEXT 0
44 Res Desc1 32-bit signed data Length in bytes of the block RES_DESC1 0
48 TrigTime Array 32-bit signed data Length in bytes of the TRIGTIME array 0
52 Ris Time Array 32-bit signed data Length in bytes of the RIS_TIME array 0
56 Res Array 1 32-bit signed data 0
60 Wave Array 1 32-bit signed data Length in bytes of the 1st data array 1,704,402
64 Wave Array 2 32-bit signed data Length in bytes of the 2nd data array 0
76 Instrument Name Null terminated string Name of the instrument LECROYWR6100A
116 Wave Array Count 32-bit signed data Number of data points (samples) in the data array 1,704,402
124 First Valid Point 32-bit signed data Number of points to skip before first good point 0
128 Last Valid Point 32-bit signed data Index of last good data point 1,704,401
156 Vertical gain float (32-bit IEEE floating point value) Vertical gain
160 Vertical offset float (32-bit IEEE floating point value) Vertical offset
172 Nominal Bits 16-bit signed data Intrinsic precision of the observation 8 bits