Cesar Pereida García: Insecure-by-default architecture leads to insecure cryptography

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In applied cryptography theory meets practice. The practical security of cryptography is as important as its theoretical security, however, often there is a disconnection between the two, leading to broken and insecure cryptography implementations. In his doctoral dissertation, MSc Cesar Pereida Garcia analyses the side-channel security of the most widely used cryptographic library, namely OpenSSL. He found out that a well-intended architecture decision to provide side-channel security, leads to multiple vulnerabilities instead.

Side-channel Analysis (SCA) focuses on practical attacks against implementations of symmetric and asymmetric cryptosystems. These cryptosystems include digital signature algorithms, public key algorithms, block ciphers, stream ciphers, hash functions, and other cryptographic primitives.

SCA focuses on the security differences between theory and practice, often created by two contrasting requirements in cryptography: performance, and security.

"Efficiency is required for practical implementations of cryptography to be usable, but achieving theoretical security leads to slow unusable implementations, thus a compromise must be reached," says Cesar Pereida García.

Unfortunately, in OpenSSL, the compromise was implemented at the architecture level by using an insecure-by-default approach, leading to multiple side-channel vulnerabilities that have been discovered and exploited over more than a decade.

His dissertation takes a closer look and answers the following research questions: 1) How secure is OpenSSL against SCA? 2) How can these vulnerabilities be prevented? 3) How can these vulnerabilities be efficiently detected?

The doctoral dissertation of MSc (Tech) Cesar Pereida García in the field of computer science titled "Side-Channel Analysis and Cryptography Engineering: Getting OpenSSL Closer to Constant-Time" will be publicly examined in the Faculty of Information Technology and Communication Sciences of Tampere University on 11 February 2022 at 12.00. Associate Prof. Yuval Yarom from University of Adelaide, Australia will be the opponent, and Associate Prof. Billy Brumley will act as the custos.

The dissertation is available online at https://urn.fi/URN:ISBN:978-952-03-2289-2

Due to the COVID-19 situation, the event can be joined via remote connection (Zoom).