Since our launch in 2012, we’ve been on a mission: to make digital identification simple and secure for everyone, and everything.
In that time, we’ve expanded constantly, and been joined by over 150 incredible people, all with the same vision. We’ve grown in other ways too we raised $35 in our Series A funding round, and launched our game-changing authentication platform.
Our technology is now being used by hundreds and thousands of users worldwide, including some of the world’s leading financial institutions.
And this is just the beginning.
Over the next year, Callsign will double in size as we continue our mission to make every web, mobile and physical interaction seamless and secure.
We can’t do that alone, though. That’s why we’re looking hire the brightest, most inquisitive minds out there: the people who want to help us change the rules of identity and have the skills and passion to make this mission a reality.
Does that sound like you? Let’s talk.
As a Senior Crypto Engineer you will be enhancing and maintaining critical components which encapsulate/perform security processing, including those which manage/handle/use cryptographic keys
- Proactively identify technical debt, where the platform can be optimized, and introduce operational efficiencies
- Design, document and implement secure, performant, scalable, highly transactional software, that adheres to functional and non-functional requirements, and be able to explain them to both technical and non-technical stakeholders
- Estimate, prioritize and execute tasks in a high-pressure environment
- Support the execution of production deployments and go-lives
- Work as part of an amazing team of like-minded individuals with a can-do attitude to change the world
- The opportunity to work in an Agile fast-paced environment, where requirements can change overnight and getting things done is as simple as making a case and leading the charge
- Highly experienced C and Linux software engineer
- Significant experience of secure programming techniques and full SDLC
- Ability to produce robust specifications and implementations of critical components
- System level programming experience on Linux
- Strong knowledge of cryptographic algorithms and their usage, trade-offs and limitations
- Proven experience of working with key management standards (X.509, PKI), cryptographic standards (PKCS#*)
- Proven experience of working with crypto libraries to develop security components/solutions using C
- Strong knowledge of the cryptographic elements within application frameworks and standards e.g. JWT, JWKS
- BSc or MSc in Computer Science or related degree from a top university
- Test Driven Development is your bread and butter. Without it, there’s just jam
- Familiarity with HSMs
- Familiarity with Windows security authentication and cryptographic frameworks
- Familiarity with low level Mobile security (iOS, Android) and associated hardware features
- Experience in working with Agile teams
- You have experience with Continuous Integration
- You can estimate, prioritize and execute tasks either by pair programming or single-handedly in a high-pressure environment
- You have an excellent command of the English language
- Health Insurance single
- Life Insurance
- Employee Assistance Program
- 3 months full pay maternity amp; 2 weeks full pay paternity (if the statutory minimum is met)
- 25 days of annual leave + Callsign Bank Holiday (not included in holiday allowance)
- Free financial advise
- Cycle to work scheme
- Wills and Estates our benefits provider has partnered with a third party who offers a discount
- Home Utilities - our benefits provider has partnered with a third party who offers a discount
- Cycle Insurance
- Health cash plans
- Cyclist protection
- Discounted gym membership