Cryptography Engineer

ABOUT THE ROLE
We are looking for an experienced Cryptography Engineer to join our R&D team and work on security-critical open source system where cryptography is a core part of the product.
You will be working at the intersection of applied cryptography, software engineering, security and modern distributed systems — analysing cryptographic constructions, designing secure protocols, implementing cryptographic primitives and their optimization in the framework.
This role is suitable for both cryptography-first engineers with a strong mathematical background and engineering-first developers who have substantial experience with cryptographic systems and want to go deeper into applied cryptography.

WHAT YOU WILL DO
Design, implement and review cryptographic protocols and security-critical components for the framework under creation.
Implement and integrate cryptographic algorithms and primitives into production software and its releases.
Work with symmetric and asymmetric cryptography, digital signatures, hashing and key-exchange mechanisms.
Design and implement secure key management and key lifecycle processes.
Analyse existing cryptographic implementations and identify potential weaknesses.
Participate in security and cryptographic code reviews.
Translate cryptographic research and academic papers into practical engineering solutions.
Develop comprehensive unit, integration, negative and interoperability tests.
Investigate vulnerabilities, implementation flaws and potential attack vectors.
Keep up with developments in applied cryptography, cryptographic protocols and emerging security technologies.

WHAT WE EXPECT
Cryptography
Strong understanding of modern cryptographic fundamentals:symmetric encryption;
asymmetric encryption;
hash functions;
MAC / HMAC;
digital signatures;
key exchange;
public-key cryptography;
random number generation;
key derivation and key management.

Practical understanding of algorithms and constructions such as:AES;
ChaCha20 / Poly1305;
SHA-2 / SHA-3;
RSA;
ECC;
ECDSA / EdDSA;
Diffie–Hellman / ECDH;
HKDF;
AEAD.

Understanding of common cryptographic protocols and how they are used in real systems.
Ability to reason about cryptographic security assumptions and threat models.
Understanding of common cryptographic implementation mistakes and attack vectors.
Ability to read and understand cryptographic papers, specifications and technical documentation.

Software Engineering
4+ years of professional software engineering experience, with significant experience working with security-critical or low-level systems.
Strong programming skills in at least one of:Rust
C/C++
Go
Python

Experience designing and implementing production-grade software.
Strong understanding of algorithms, data structures and software architecture.
Experience with unit testing, integration testing and code review.
Understanding of networking and modern distributed systems.
Good understanding of operating-system concepts and how applications interact with system resources.
Experience working with APIs, protocols and serialization formats.

Security
Understanding of threat modelling and security boundaries.
Understanding of authentication, authorization and trust models.
Familiarity with secure software development practices.
Ability to distinguish between a cryptographic problem and a problem that should be solved by another security control.
Experience analysing security vulnerabilities and their potential impact.

WOULD BE A PLUS
Experience with Rust and/or cryptographic libraries.
Experience developing cryptographic libraries or security-critical components.
Experience with TLS, PKI, X.509, certificates and key management systems.
Knowledge of modern protocols such as HPKE.
Experience with zero-knowledge proofs, MPC, threshold cryptography or homomorphic encryption.
Experience with blockchain cryptography and transaction privacy.
Knowledge of secure distributed computing.
Experience with hardware-backed security, HSM, TPM, Secure Enclave or similar technologies.
Experience with side-channel attacks and constant-time programming.
Contributions to open-source cryptographic or security projects.
Academic or professional background in cryptography, information security, mathematics or computer science.
Publications, conference talks or research experience in cryptography/security.

WHAT WE OFFER
Work on technically challenging security-critical problems.
Opportunity to work with modern applied cryptography rather than only standard application security.
Direct involvement in real open source system development.
Collaboration with experienced software engineers and network engineers.
Flexible remote / hybrid work.
Competitive compensation.
Paid vacation and sick leave.