How cryptography works
Symmetric cryptography uses one shared key to encrypt and decrypt, which is fast and suited to large amounts of data. Asymmetric cryptography uses a public and private key pair, enabling secure key exchange and digital signatures without sharing a secret in advance.
Hash functions create fixed-length fingerprints of data to verify integrity. Protocols such as TLS combine these building blocks. Security depends on strong, well-reviewed algorithms and careful key management, since most failures come from poor implementation or exposed keys rather than broken mathematics.
Why it matters for Canadian organizations
Cryptography protects personal information in transit and at rest, which supports the safeguarding duties under PIPEDA and Law 25. Encrypted data that is lost or stolen is often far less likely to cause real risk of significant harm.
The Canadian Centre for Cyber Security publishes guidance on approved cryptographic algorithms and key lengths, and standards such as PCI DSS and OSFI B-13 expect appropriate cryptographic controls. Planning is also under way across the industry for the eventual transition to quantum-resistant algorithms.
How to implement it
Use well-established, standard algorithms and libraries rather than inventing your own. Enforce current TLS versions on all services, encrypt sensitive data at rest, and hash passwords with slow, salted functions designed for the purpose.
Manage keys carefully: generate them securely, store them in a hardware security module or managed key service, rotate them, and limit who can use them. Keep an inventory of where cryptography is used, so weak or deprecated algorithms can be retired and future migrations planned. Plan ahead for migration to quantum-resistant algorithms as standards mature.
Frequently asked questions
What is the difference between cryptography and encryption?
Cryptography is the broad field covering many techniques, including hashing, signatures, and key exchange. Encryption is one specific use of cryptography that makes data unreadable without the correct key. Put simply, encryption is a tool within the toolbox that cryptography provides.
What are the main types of cryptography?
The main types are symmetric key cryptography, asymmetric (public key) cryptography, and cryptographic hash functions. Real systems typically combine all three, for example in a TLS connection to a website. Each is suited to different tasks, and strong systems use them together.
Can cryptography be broken?
Well-designed modern algorithms are not practically breakable by brute force, but implementations, weak keys, and poor key handling can be exploited. Future quantum computers may threaten some public key algorithms, which is driving new standards.
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