1. A method of obfuscating a code, the method comprising:
performing a first level obfuscating technique on a code to generate a first obfuscated code,
performing a second level obfuscating technique on the first obfuscated code.
2. The method according to claim 1,
wherein one of the obfuscating techniques or both of them isare based on a hardware technique.
3. The method according to claim 2,
wherein the one obfuscating technique is performed by using an address translation unit.
4. The method according to claim 2,
wherein the other one of the obfuscating techniques is based on a software technique.
5. The method according to claim 1,
wherein one of the first level obfuscating technique and of the second level obfuscating technique comprises a mapping step, wherein the mapping is performed between an address space of an execution path and an obfuscated address space for retrieving the obfuscated code from a memory.
6. The method according to claim 5,
wherein the mapping is based on a space filling curve.
7. The method according to claim 1,
wherein one of the first level obfuscating technique and of the second level obfuscating technique comprises a mapping step, wherein the mapping step is based in a parametric mapping function using a secret as a parameter of the mapping function.
8. The method according to claim 1,
wherein the first level obfuscating technique reorders code blocks with a size of a cache line, andor
wherein the second level obfuscating technique is based on a local permutation inside the each code block.
9. The method according to claim 1,
wherein the obfuscated code of the second level obfuscating technique is used as an additional input for the obfuscation of the first level obfuscating technique.
10. The method according to claim 1, further comprising
performing of a third or higher level obfuscating technique.
11. A processing system comprising:
a processor with a cache,
an external memory, and
an address translation unit,
wherein the address translation unit is arranged between the cache and the external memory, and
wherein the processing system is adapted to perform a method according to claim 1.
12. A program element, which, when being executed by a processor, is adapted to control or carry out a method according to claim 1.
13. A computer-readable medium, in which a computer program is stored which, when being executed by a processor, is adapted to control or carry out a method according to claim 1.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A process for preparing at least one cyclic compound with Z cycles and 7 to 16 carbon atoms with a keto group, at least comprising the stages:
(a1) oxidation of a composition (A), at least comprising one cyclic olefin with Z cycles and 7 to 16 carbon atoms and at least two C\u2014C double bonds, by means of dinitrogen monoxide to give a composition (A1), at least comprising
the at least one cyclic compound with Z cycles and 7 to 16 carbon atoms with a keto group,
the at least one cyclic olefin with Z cycles and 7 to 16 carbon atoms with at least two C\u2014C double bonds and
at least one compound with Z\u22121 cycles and 7 to 16 carbon atoms with at least one aldehyde group,
(a2) separating off the at least one cyclic olefin with Z cycles and 7 to 16 carbon atoms with at least two C\u2014C double bonds from the composition (A1) from stage (a1) in order to obtain a composition (A2), at least comprising
the at least one cyclic compound with Z cycles and 7 to 16 carbon atoms with a keto group and
at least one compound with Z\u22121 cycles and 7 to 16 carbon atoms with at least one aldehyde group, and
(b) distillative treatment of the composition (A2) from step (a2) in order to obtain a composition (B), comprising
the at least one cyclic compound with Z cycles and 7 to 16 carbon atoms with a keto group and
less than 1.0% by weight of the at least one compound with Z\u22121 cycles and 7 to 16 carbon atoms with at least one aldehyde group,
where Z can be 1, 2, 3 or 4.
2. The process according to claim 1, which comprises at least the following stages:
(a1) oxidation of a composition (A), at least comprising one cyclic olefin with Z cycles and 7 to 16 carbon atoms and at least two C\u2014C double bonds, by means of dinitrogen monoxide to give a composition (A1), at least comprising
the at least one cyclic compound with Z cycles and 7 to 16 carbon atoms with a keto group,
at least one cyclic compound with Z cycles and 7 to 16 carbon atoms with at least two keto groups,
the at least one cyclic olefin with Z cycles and 7 to 16 carbon atoms with at least two C\u2014C double bonds and
at least one compound with Z\u22121 cycles and 7 to 16 carbon atoms with at least one aldehyde group,
(a2) separating off the at least one cyclic olefin with Z cycles and 7 to 16 carbon atoms with at least two C\u2014C double bonds from the composition (A1) from stage (a1) in order to obtain a composition (A2), at least comprising
the at least one cyclic compound with Z cycles and 7 to 16 carbon atoms with a keto group,
at least one cyclic compound with Z cycles and 7 to 16 carbon atoms with at least two keto groups and
at least one compound with Z\u22121 cycles and 7 to 16 carbon atoms with at least one aldehyde group, and
(b) distillative treatment of the composition (A2) from step (a2) in order to obtain a composition (B), comprising
the at least one cyclic compound with Z cycles and 7 to 16 carbon atoms with a keto group,
less than 0.5% by weight of the at least one cyclic compound with Z cycles and 7 to 16 carbon atoms with at least two keto groups and
less than 1.0% by weight of the at least one compound with Z\u22121 cycles and 7 to 16 carbon atoms with at least one aldehyde group.
3. The process according to claim 1, wherein stage (b) is followed by at least the following stage (c):
(c) hydrogenation of the composition (B) in the presence of at least one catalyst in order to obtain a composition (C).
4. The process according to claim 1, wherein stage (b) is followed by at least the following stage (d):
(d) treatment of the composition (B) with at least one base in order to obtain a composition (D).
5. The process according to claim 4, wherein stage (d) is followed by at least the following stage (c\u2032):
(c\u2032) hydrogenation of the composition (D) in the presence of at least one catalyst in order to obtain a composition (C\u2032).
6. The process according to claim 3, wherein stage (c) or (c\u2032) is followed by at least the stage (e):
(e) purification of the composition (C) from step (c) or (C\u2032) from step (c), at least comprising the steps
(e1) thermal treatment of the composition (C) or (C\u2032) with at least one acid, or at least one catalyst which comprises at least one transition metal,
(e2) further purification by a process selected from the group consisting of distillation, extraction and crystallization.
7. The process according to claim 1, wherein the cyclic olefin is cyclododecatriene.
8. The process according to claim 1, wherein the cyclic olefin is cyclododecatriene which has been prepared by trimerization of butadiene.
9. The process according to claim 1, wherein the at least one cyclic olefin with Z cycles and 7 to 16 carbon atoms and at least two C\u2014C double bonds is selected from the group consisting of 1,5-cyclooctadiene, 1,5-cyclododecadiene, 1,9-cyclohexadecadiene, 1,8-cyclotetradecadiene, 1,6-cyclododecadiene, 1,6,11-cyclopentadecatriene, 1,5,9-cyclododecatriene, vinylcyclohexene, norbornadiene, ethylidenenorbornene and mixtures thereof.
10. The process according to claim 4, wherein the base is selected from the group consisting of sodium hydroxide, potassium hydroxide and mixtures thereof.