What is Encryption in Payments?
Encryption is the process of converting readable data (plaintext) into an unreadable format (ciphertext) using a mathematical algorithm and an encryption key. In payments, encryption protects card numbers, security codes, and personal data as they are transmitted and stored, preventing unauthorised access.
How Payment Encryption Works
When card data is encrypted, it is scrambled using an encryption algorithm and a secret key. Only someone with the corresponding decryption key can convert it back to readable form. Even if encrypted data is intercepted, it is useless without the key.
Types of Encryption in Payments
Transport Layer Security (TLS)
TLS encrypts data as it travels between systems — for example, between a customer's browser and a payment server. This is what creates the HTTPS connection you see when making online payments. TLS protects data in transit but not at rest.
AES Encryption
Advanced Encryption Standard (AES) is used to encrypt stored data. AES-256 (256-bit key length) is the standard required by PCI DSS for encrypting stored cardholder data. It would take billions of years to crack with current technology.
Point-to-Point Encryption (P2PE)
P2PE encrypts card data at the point of capture (the card reader or phone keypad) and keeps it encrypted until it reaches the payment processor's secure decryption environment. The merchant never has access to unencrypted card data.
Encryption and PCI DSS
PCI DSS requires encryption in several contexts:
- Cardholder data must be encrypted when transmitted across open or public networks
- Stored cardholder data must be rendered unreadable (encryption is one approved method)
- Encryption keys must be managed securely with restricted access
Paytia uses AES-256 encryption to protect all payment data processed through its platform. When a customer enters card details during a phone payment via DTMF suppression, the data is encrypted at the point of capture and remains encrypted throughout its journey to the payment processor. Your business systems never handle unencrypted card data.
Frequently Asked Questions
What is the difference between encryption and tokenisation?
Encryption scrambles data using a mathematical algorithm — it can be reversed with the correct key. Tokenisation replaces data with a random token that has no mathematical relationship to the original — it cannot be reversed. Both protect card data but work differently.
Is encrypted card data still in PCI DSS scope?
It depends. If your systems have access to the decryption keys, encrypted card data is still in scope. If the data is encrypted by a third party and you never have the keys (as with P2PE), it can be considered out of scope for your PCI assessment.
What encryption standard does PCI DSS require?
PCI DSS requires strong cryptography for protecting cardholder data. AES-256 is the most commonly used standard. The specific requirements are detailed in PCI DSS Requirement 3 (protect stored data) and Requirement 4 (encrypt transmissions).
See how Paytia handles encryption
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