**Simona Samardjiska**

**Ph.D. started in: **2010**Year of graduation: **2015**COINS consortium member: **Norwegian University of Science and Technology**Supervised by:** Danilo Gligoroski**Links:** **Research area: **Cryptography**Project title:** Multivariate Public Key Algorithms Produced by Quasigroups**Project description:** Multivariate public key cryptography is an active research area considered as one of the post-quantum alternatives to the classical public key algorithms based on the integer factorization and discrete logarithm problem such as RSA or ECC. Multivariate schemes, also known as MQ (multivariate quadratic) schemes have also significant performance advantages over the classical algorithms, especially on multicore architectures, because of their highly parallelizable nature.

My PhD research is focused on the theoretical aspects, analysis and improvement of the existing schemes as well as creating new

primitives in the family of MQQ (Multivariate Quadratic Quasigroups) public key cryptosystems. The MQQ family is

based on elements from quasigroup theory, and was introduced by Gligoroski et al. in 2008 with the MQQ encryption

scheme.

**Publications:**

- Jean-Charles Faugère, Danilo Gligoroski, Ludovic Perret,
**Simona Samardjiska**, Enrico Thomae (2015). A Polynomial-Time Key-Recovery Attack on MQQ Cryptosystems **Simona Samardjiska**(2015). Multivariate Public Key Cryptosystems Produced by Quasigroups**Simona Samardjiska**, Danilo Gligoroski (2015). Approaching maximum embedding efficiency on small covers using Staircase-Generator codes- Danilo Gligoroski, Hristina Mihajloska,
**Simona Samardjiska**, Håkon Jacobsen, Rune Erlend Jensen, Mohamed Ezzat El Hadedy Aly (2014). Pi-Cipher: Authenticated Encryption for Big Data - Danilo Gligoroski, Hristina Mihajloska,
**Simona Samardjiska**, Håkon Jacobsen, Rune Erlend Jensen, Mohamed El-Hadedy (2014). CAESAR candidate PiCipher - Danilo Gligoroski,
**Simona Samardjiska**(2014). iSHAKE: Incremental Hashing With SHAKE128 and SHAKE256 for the Zettabyte Era **Simona Samardjiska**, Danilo Gligoroski (2014). Linearity Measures for Multivariate Public Key Cryptography- Danilo Gligoroski,
**Simona Samardjiska**, Håkon Jacobsen, Sergey Bezzateev (2013). McEliece in the world of Escher - Danilo Gligoroski,
**Simona Samardjiska**, Håkon Jacobsen, Sergey Bezzateev (2013). McEliece in the world of Escher - Håkon Jacobsen,
**Simona Samardjiska**, Danilo Gligoroski (2013). On the strong and weak keys in MQQ-SIG **Simona Samardjiska**(2013). Identity Based Encryption**Simona Samardjiska**, Danilo Gligoroski (2013). On a Class of Quadratic Permutation Polynomials Over F_(2^n)**Simona Samardjiska**, Danilo Gligoroski (2013). On a Class of Quadratic Permutation and Quasigroup Polynomials Over Finite Fields of Characteristic 2**Simona Samardjiska**, Danilo Gligoroski (2013). Towards a Characterization of Left Quasigroup Polynomials of Small Degree Over Fields of Characteristic 2**Simona Samardjiska**, Danilo Gligoroski (2013). Towards a secure Multivariate Identity-Based Encryption- Danilo Gligoroski,
**Simona Samardjiska**(2012). The Multivariate Probabilistic Encryption Scheme MQQ-ENC - Danilo Gligoroski,
**Simona Samardjiska**(2012). The Multivariate Probabilistic Encryption Scheme MQQ-ENC - Håkon Jacobsen,
**Simona Samardjiska**, Danilo Gligoroski (2012). On the strong and weak keys in MQQ-SIG **Simona Samardjiska**(2012). The MQQ family of multivariate public key cryptosystems**Simona Samardjiska**, Yanling Chen, Danilo Gligoroski (2012). Algorithms for construction of multivariate quadratic quasigroups (MQQs) and their parastrophe operations in arbitrary Galois fields**Simona Samardjiska**, Danilo Gligoroski (2012). Left MQQs whose left parastrophe is also quadratic**Simona Samardjiska**, Danilo Gligoroski (2012). Towards a Secure Multivariate Identity-Based Encryption**Simona Samardjiska**, Danilo Gligoroski (2012). Towards a secure Multivariate Identity-Based Encryption- Danilo Gligoroski, Svein Johan Knapskog,
**Simona Samardjiska**(2011). The Need for Parallel Ultra Fast Cryptographic Designs for Emerging Technologies - Danilo Gligoroski,
**Simona Samardjiska**(2011). The Public Key Encryption Scheme MQQ-ENC **Simona Samardjiska**(2011). On Some Cryptographic Properties of the Polynomial Quasigroups**Simona Samardjiska**(2011). Permutation Polynomials and Polynomial Quasigroups Defined over Z_p^w**Simona Samardjiska**(2011). Quasigroup Models of Asymmetric Cryptographic Primitives**Simona Samardjiska**, Yanling Chen, Danilo Gligoroski (2011). Construction of Multivariate Quadratic Quasigroups (MQQs) in Arbitrary Galois Fields**Simona Samardjiska**, Danilo Gligoroski (2011). Identity-Based Identification Schemes Using Left Multivariate Quasigroups**Simona Samardjiska**, Danilo Gligoroski (2011). On a Class of Left MQQs with Degree Invariant to Parastrophy**Simona Samardjiska**, Danilo Gligoroski (2011). On a Class of Left MQQs with Degree Invariant to Parastrophy- Smile Markovski, Vesna Dimitrova,
**Simona Samardjiska**(2010). Identity sieves for quasigroups - Smile Markovski,
**Simona Samardjiska**, Danilo Gligoroski, Svein Johan Knapskog (2010). Multivariate Trapdoor Functions Based on Multivariate Left Quasigroups and Left Polynomial Quasigroups **Simona Samardjiska**, Smile Markovski, Danilo Gligoroski (2010). Multivariate Quasigroups Defined by T-functions

**Events attended with COINS funding:**

- COINS seminar on linear attacks in MQ cryptography, Bergen, Norway, 2015
- COINS Ph.D. student seminar, Tromsø, Norway, 2014
- COINS Ph.D. student seminar, Stavanger, Norway, 2013
- NISK, Stavanger, Norway, 2013
- FRISC Finse winter school, Finse, Norway, 2013