Enhancing Security: PAN Removal and Secure Hashing - I

In today's ever-evolving digital landscape, the protection of sensitive data stands as a top priority for organizations across various industries. Safeguarding critical information, such as Primary Account Numbers (PANs), is of utmost importance to ensure the confidentiality and integrity of customer data. One essential aspect of data security is the implementation of cleartext PAN removal, a defense-in-depth control mechanism designed to fortify data protection against unauthorized access. In this comprehensive article, we will delve into the significance of cleartext PAN removal and explore the implementation of secondary independent control systems to prevent breaches. Additionally, we will examine the utilization of keyed cryptographic hashing algorithms, incorporating randomly generated secret keys, as a robust measure to resist brute force attacks and ensure secret authentication integrity.

I.  Understanding Cleartext PAN Removal:

In the realm of data security, the term "cleartext PAN" refers to the storage of Primary Account Numbers in an unencrypted and easily readable format. Storing PANs in cleartext poses a significant risk, as it leaves the data vulnerable to unauthorized access. To mitigate this risk, organizations employ the practice of cleartext PAN removal, which involves encrypting or hashing the PAN before storage.

When a PAN is encrypted, it is transformed into an unreadable form using an encryption algorithm and a corresponding encryption key. This ensures that even if an unauthorized individual gains access to the stored data, they would not be able to decipher the PAN without the encryption key. Encryption provides a high level of security but comes with the need to manage encryption keys securely to prevent unauthorized access.

Alternatively, organizations can employ cryptographic hashing algorithms to convert PANs into fixed-length hash values or digests. Hashing algorithms, such as SHA-256 (Secure Hash Algorithm 256-bit), apply a one-way process to the PAN, generating a unique hash value. This hash value is mathematically derived from the PAN but cannot be reversed to retrieve the original PAN. Therefore, even if an attacker gains access to the hashed PANs, they would not be able to retrieve the original PAN without engaging in a computationally expensive and time-consuming process known as brute force attack.

II. Secondary Independent Control Systems:

While cleartext PAN removal significantly enhances data security, organizations must implement secondary independent control systems to protect against potential breaches. These control systems act as an additional layer of defences, safeguarding the confidentiality of stored PANs even if the primary access control system is compromised.

Cryptographic Key Management:

One crucial aspect of secondary independent control systems is cryptographic key management. Cryptographic keys play a vital role in encryption, decryption, and hashing processes. By effectively managing these keys, organizations can ensure that only authorized individuals have access to the keys required to decrypt sensitive data or validate the integrity of hashed PANs.

Cryptographic key management involves various practices, including:

a) Access Controls: Strict access controls should be enforced to limit access to cryptographic keys. Only authorized personnel should have the necessary permissions to retrieve, use, or modify the keys.

b) Separation of Duties: Implementing separation of duties ensures that no single individual possesses complete control over the entire key management process. Dividing responsibilities among multiple individuals reduces the risk of unauthorized key access or misuse.

c) Key Rotation: Regular key rotation is essential to mitigate the impact of a compromised key. By frequently changing cryptographic keys, organizations can minimize the window of opportunity for attackers to exploit a stolen or compromised key.

Cryptography and Decryption Key Governance:

In addition to cryptographic key management, governance over cryptography and decryption keys is crucial for establishing a robust secondary independent control system. This governance framework outlines policies, procedures, and controls for the secure generation, distribution, usage, and destruction of keys.

The governance framework for cryptography and decryption keys should address the following:

a) Key Generation: Keys should be generated using strong random number generators to ensure their unpredictability and resistance to cryptographic attacks.

b) Key Distribution: Secure distribution mechanisms, such as secure channels or hardware security modules (HSMs), should be employed to transmit keys to authorized parties.

c) Key Usage: Proper controls should be in place to monitor and track the usage of keys. This includes logging key access, usage, and revocation activities.

d) Key Destruction: When keys are no longer needed or compromised, they should be securely destroyed to prevent unauthorized access to sensitive data.

To Read Part 2, Click here