# Tresorit

Tresorit is a cloud storage platform that offers functions for administration, storage, synchronization, and transfer of data using end-to-end encryption.
Founded in 2011, Tresorit closed an €11.5M Series B financing round in 2018 and was featured on FT1000 by the Financial Times 2020 as the fifth fastest-growing cybersecurity company in Europe. In 2021, Swiss Post Communications Services acquired a majority stake in the company to expand its digital product portfolio. Tresorit works as an independent entity under Swiss Post. which is now sole shareholder. The company has offices in Zurich, Switzerland; Munich, Germany; and Budapest, Hungary, employing around 100 people.

## History

Tresorit was founded in 2011 by Istvan Lam, Szilveszter Szebeni and Gyorgy Szilagyi with the aim of providing a secure alternative to traditional cloud storage solutions. In the coming years, Andrea Skaliczki joined as CFO, Istvan Hartung as CTO. The company officially launched its client-side encrypted cloud storage service after emerging from its stealth beta version in April 2014.
In 2013 and 2014, Tresorit hosted a hacking contest offering $10,000 to anyone who hacked their data encryption methods to gain access to their servers. After some months, the reward was increased to $25,000 and later to $50,000, challenging experts from institutions like Harvard, Stanford or MIT. The contest ran for 468 days and according to the company, nobody was able to break the encryption.
In August 2015, Wuala (owned by LaCie and Seagate), a pioneer of secure cloud storage, announced it was closing its service after 7 years and recommended its users choose Tresorit as their secure cloud alternative.
In 2016, Tresorit launched its NGO initiative with the aim of improving the digital security of non-profits and has gained notable recognition within the sector where the protection of sensitive information is paramount. More than 500 teams (human rights defenders, environmental activists, teams working on education and research, and many others from all over the world) joined Tresorit’s NGO program since then.
In 2017, Tresorit patented its shareable encryption technology in the US under no. US 9563783 B2, and LogMeIn co-founder Marton Anka joined Tresorit as an investor and advisor.
In 2019, Tresorit reached the number of 100 employees, and Tresorit improved its governance feature set with e-mail verification and detailed user reports.
In 2020, during the COVID-19 pandemic, Tresorit offered free access to remote work solutions for public education and healthcare institutions. The company was named the 2020 Gartner Peer Insights Customers’ Choice for Content Collaboration Tools.
In July 2021, Tresorit was acquired by the Swiss Post to further expand its presence in its core German-speaking markets, including Germany, Austria, and Switzerland.
In 2022, Tresorit launched a new email encryption tool, added eSignature feature to its cloud collaboration platform and introduced qualified eSignatures for its Swiss customers.
In June 2023, Tresorit announced the appointment of István Hartung as CEO. The previous CEO and founder, István Lám, remained member of the Board of Tresorit Group but transitioned to the role of Director of Corporate Development.

## Technology

Tresorit uses AES 256 encryption. With Tresorit's end-to-end encryption, every file and relevant metadata on user devices are encrypted with unique, randomly generated encryption keys. These keys are never sent to Tresorit's servers in an unencrypted format. Accessing files is only possible with a user's unique private decryption key.
Tresorit uses random keys for each file and random IVs for each version of a file. The company claims that two identical files look completely different after encryption, thus they cannot be compared or matched.
Tresorit provides client side zero-knowledge encryption, across all platforms, even from web browsers. This ensures that no keys, passwords, files or any sensitive material ever get transferred in an unencrypted or reversible form. Encryption keys or unencrypted files are never visible to the servers or Tresorit administrators. Due to this zero-knowledge system, Tresorit does not even store passwords. Administrators of a business Tresorit account can reset user passwords, if the business has the feature "Advanced Control" turned on. This design enhances user privacy and security.

## Services

Tresorit SecureCloud is an encrypted cloud storage which enables users to work together securely in the cloud.
Tresorit FileSharing is a secure internal and external file sharing that allows users to stay in control when sending and receiving files externally.
Tresorit EmailEncryption is a tool that works together with popular email services such as Microsoft Outlook or Google Gmail as a built-in module and enables the sending of secure emails.
Tresorit eSign is a function to digitally sign documents with a simple electronic signature (SES). The signature of each contracting party is linked to the document in question to prove their agreement with its content.

## Reception

In 2017, Tresorit was named one of the Rising Stars at Deloitte's Technology Fast 50 Central Europe Award. In 2019, Tresorit was named as a Global Leader in Cloud Computing at the Stratus Awards. In 2020, Tresorit was named a 2020 Gartner Peer Insights Customers' Choice for Content Collaboration Tools and was featured on FT1000 by Financial Times 2020 as the fifth fastest-growing cybersecurity company in Europe. In 2022, Tresorit was named a Customers’ Choice in the 2022 Gartner Peer Insights ‘Voice of the Customer’: Content Collaboration Tools for the second consecutive year. Tresorit has attained the highest overall rating of 4.7 out of 5 in this category. In 2023, Tresorit won the Next Gen Zero Trust Award at the 11th Annual Global InfoSec Awards at the RSA Conference.
ITPro called Tresorit it a “seriously secure cloud collaboration and file-sharing service” that is "perfect for handling confidential data”. TechCrunch refers to Tresorit as the “early European pioneer” in end-to-end-encrypted cloud services while the Mashable highlights that Tresorit’s “strength lies in its security” as it offers end-to-end encryption and the ability to keep a very close eye on who is accessing users’ files. Tresorit was featured as one of the secure file sharing tools in The New York Times Simple Online Security series and was listed in The Mac Observer's top five encrypted cloud storage services.