Cryptography overview

Security is built into every stage of development — from the first idea to the final release. This section describes the cryptographic model, algorithms, and data protection mechanisms that make Passwork trusted by thousands of businesses worldwide.

Who this section is for

• Information security specialists — for audits and compliance assessments
• Technical decision-makers — for evaluating the product before deployment
• Administrators — for understanding how the system works and how to configure it

How we build secure software

Practice	Description
Security champions	OWASP training and threat modeling in every development team
DevSecOps approach	Static & dynamic analysis, SCA, IaC scanners integrated into every build
Multi-stage review	No direct pushes to main branch, mandatory security code review
External audits	Annual penetration testing and security audits by independent experts

Standards and validation

• ISO 27001 certified — all development and infrastructure practices meet the highest security standards
• Tested by HackerOne — independent security assessments by ethical hackers
• GDPR compliant — full compliance with European data protection regulations

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Zero-Knowledge architecture

Passwork is built on the Zero-Knowledge principle: the server does not have enough information to decrypt user data. Neither server administrators nor technical staff can access your passwords — even if they wanted to.

• The master password never leaves the user's device
• All cryptographic keys are generated on the client
• The server stores only encrypted data and encrypted keys
• Decryption is only possible on the client side

This architecture ensures your passwords never leave your infrastructure, making Passwork trusted by government agencies and highly regulated organizations across Europe.

Two-level protection

Passwork applies two levels of encryption:

Level	Where it runs	Key	When active
Client-side encryption	Browser / app	User keys	When CSE is enabled
Server-side encryption	Server	Server key	Always

Even with client-side encryption disabled, data is still protected by server-side encryption with AES-256.

Algorithms used

Purpose	Algorithm	Parameters
Key derivation from password	PBKDF2	SHA-256, 300K iterations
Symmetric encryption (server)	AES-256-CFB	OpenSSL
Symmetric encryption (client)	AES-256-CBC	+ Base32 encoding
Asymmetric encryption	RSA-OAEP	2048 bit, SHA-256
Hashing	SHA-256, SHA-512	—

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Section structure

Fundamentals

• Glossary — definitions: master password, master key, vault, record, keys
• Data model — object hierarchy and relationship with cryptographic keys

Encryption

• Encryption scope — which fields are encrypted on the client, which on the server
• Key hierarchy — key chain from master password to attachment keys
• Cryptographic algorithms — specifications for PBKDF2, AES, RSA

Processes

• Authentication — master password verification and access workflow
• Local storage — saving master key in the browser
• Record sharing — internal sharing and external links

Infrastructure

• Server-side encryption — AES-256-CFB, key management, rotation
• Session tokens — Access Token, Refresh Token, CSRF protection

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Encryption chain overview

Client side:

1. Master password (entered by user) → PBKDF2 (300K iterations) →
2. Master key (512 bits) → AES-256-CBC →
3. Private RSA key (2048 bits) → RSA-OAEP (WebCrypto) →
4. Vault key (256 bits) → AES-256-CBC →
5. Record key (256 bits) → AES-256-CBC →
6. Record data (passwords, secrets, files — encrypted)

Server side:

7. Server key (256 bits, OpenSSL) → AES-256-CFB →
8. Database (double encryption)

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What is encrypted on the client

Not all data is encrypted on the client — some fields are protected only by server-side encryption to enable search and sorting functionality.

Detailed information about encryption of each field is in the Encryption scope section.

Key parameters

Parameter	Value
RSA key	2048 bits
AES key	256 bits
PBKDF2 iterations (client)	300,000
PBKDF2 iterations (server)	600,000
Access Token entropy	256 bits
Link token entropy	256 bits
Vault key entropy	~596 bits

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Industry standards compliance

Parameter	Passwork	NIST recommendations (2024)	Status
Symmetric encryption	AES-256	AES-128/192/256	✓
Asymmetric encryption	RSA-2048	RSA-2048+	✓
Hashing	SHA-256/512	SHA-2 family	✓
PBKDF2 iterations	300K/600K	≥310K (SHA-256)	✓
Random number generator	CSPRNG	CSPRNG	✓

LLM version