Charles Guillemet became chief technology officer of Ledger on December 5, 2019, the hardware wallet maker said in a Paris-dated release1. Cointelegraph reported the appointment the same day, saying Ledger shared the release with the outlet on December 5, 20192. Guillemet kept his existing security duties on top of the new title, both sources said.
The second executive hire at Ledger on the record since 2018
Every move CryptoLately has verified there, by the day it became public
Moves: The Moves Ledger, CryptoLately's record of verified leadership moves, Oct. 3, 2016 to Oct. 2, 2026.
Read the chart as a table
| Date | Event |
|---|---|
| Nov. 26, 2018 | Skalkotos became Global Head of Ledger Vault. Demetrios Skalkotos was named Global Head of Ledger Vault of Ledger |
| April 24, 2019 | Gauthier became CEO. Pascal Gauthier was named Chief Executive Officer of Ledger |
| Dec. 5, 2019 | Guillemet became CTO. Charles Guillemet was named Chief Technology Officer of Ledger |
| March 20, 2026 | Andrews became CFO. John Andrews was named Chief Financial Officer of Ledger |
| Sept. 9, 2026 | Blatman became Chief Information Officer. Oded Blatman was named Chief Information Officer and Chief Security Officer of Ledger |
11 executive hires on the record in 2019
Executive hires CryptoLately has verified, by year
- 2019: 11
- 2017, 2018, 2020, 2021, 2022, 2023, 2024
Moves: The Moves Ledger, CryptoLately's record of verified leadership moves, Oct. 3, 2016 to Oct. 2, 2026.
Read the chart as a table
| Item | Value |
|---|---|
| 2017 | 2 |
| 2018 | 8 |
| 2019 | 11 |
| 2020 | 12 |
| 2021 | 27 |
| 2022 | 37 |
| 2023 | 20 |
| 2024 | 39 |
The move
Guillemet had joined Ledger in 20171. There, he founded Ledger's security department and its evaluation lab, Ledger Donjon. Guillemet explained his own view of the new title. “Throughout my time at Ledger I have had the pleasure of leading a world class team of security researchers that has set the standard for blockchain security,” he said. “Security and technology go hand and hand at Ledger, so my appointment to CTO is a natural extension of the critical work we are doing everyday to improve the security of the products we build”.
Pascal Gauthier, Ledger's chief executive, framed the pick around trust. “Charles has played a pivotal role in building Ledger into the security company it is today,” Gauthier said. “We are proud to have the industry's top security mind on our team and are confident that his appointment to CTO will further enhance Ledger's security technology in an increasingly connected world where hackers are becoming more sophisticated”1.
Before and after the title
Guillemet ran security assessments for Ledger's products1. He also got independent security checks done on the Ledger Nano S and Ledger Nano X, the release said. Cointelegraph added a third fact. His Donjon team had disclosed vulnerabilities in competitor devices, work the outlet said raised security standards industry-wide2. Before Ledger, Guillemet worked as a technical manager at a CEA-LETI security evaluation lab.
What came next
Guillemet still held the CTO title more than six years later, in April 20263. CoinDesk named him CTO in an April 5, 2026 report. In it, Guillemet said artificial intelligence was cutting the cost of attacking crypto systems. "Finding vulnerabilities and exploiting them becomes really, really easy," Guillemet said. "The cost is going down to zero". CoinDesk cited DefiLlama data putting crypto hacks and exploits at $1.4 billion over the prior year. That scale pushed Guillemet toward formal verification and hardware-based security, he told the outlet.
Sources
- Ledger, "Ledger Appoints Charles Guillemet as Chief Technology Officer," December 5, 2019, https://www.ledger.com/ledger-appoints-charles-guillemet-as-chief-technology-officer
- Joeri Cant, "Crypto Cybersecurity Firm Ledger Hires In-House Security Officer As New CTO," Cointelegraph, December 5, 2019, https://cointelegraph.com/news/crypto-cybersecurity-firm-ledger-hires-in-house-security-officer-as-new-cto
- Krisztian Sandor, "AI is making crypto's security problem even worse, Ledger CTO warns," CoinDesk, April 5, 2026, https://news.google.com/rss/articles/CBMiqwFBVV95cUxPQnNRNWxoR0hfMkFhSmMxMnNJemRwVlJNOHV2SlRNekZSYkNiSlc0clBEQUxYV2RMN2VPU1lLdXc0N1RGV1l5YkIyUmlKZ3NCTFRvR0lEX19wUkxqY09DX0tHTnctYzdnRTYyM0xodXBHcDNYamg5OUlVNFNYQlJXLXp3YXBWU3k2VHk5NE83ODFLVDZncDNVNlZHbkhsQjdMNl94ZWtDWi1JNlU?oc=5