This vulnerability exposes encrypted data to attacks whose goal is to recover the plaintext.
Encryption algorithms are essential for protecting sensitive information and ensuring secure communications in a variety of domains. They are used for several important reasons:
When selecting encryption algorithms, tools, or combinations, you should also consider two things:
In today’s cryptography, the length of the key directly affects the security level of cryptographic algorithms.
Note that depending on the algorithm, the term key refers to a different mathematical property. For example:
If an application uses a key that is considered short and insecure, the encrypted data is exposed to attacks aimed at getting at the plaintext.
In general, it is best practice to expect a breach: that a user or organization with malicious intent will perform cryptographic attacks on this data after obtaining it by other means.
After retrieving encrypted data and performing cryptographic attacks on it on a given timeframe, attackers can recover the plaintext that encryption was supposed to protect.
Depending on the recovered data, the impact may vary.
Below are some real-world scenarios that illustrate the potential impact of an attacker exploiting the vulnerability.
By modifying the plaintext of the encrypted message, an attacker may be able to trigger additional vulnerabilities in the code. An attacker can
further exploit a system to obtain more information.
Encrypted values are often considered trustworthy because it would not be possible for a
third party to modify them under normal circumstances.
When encrypted data contains personal or sensitive information, its retrieval by an attacker can lead to privacy violations, identity theft, financial loss, reputational damage, or unauthorized access to confidential systems.
In this scenario, the company, its employees, users, and partners could be seriously affected.
The impact is twofold, as data breaches and exposure of encrypted data can undermine trust in the organization, as customers, clients and stakeholders may lose confidence in the organization’s ability to protect their sensitive data.
In many industries and locations, there are legal and compliance requirements to protect sensitive data. If encrypted data is compromised and the plaintext can be recovered, companies face legal consequences, penalties, or violations of privacy laws.
Here is an example of a private key generation with RSA:
$config = [
"digest_alg" => "sha512",
"private_key_bits" => 1024, // Noncompliant
"private_key_type" => OPENSSL_KEYTYPE_RSA,
];
$res = openssl_pkey_new($config);
$config = [
"digest_alg" => "sha512",
"private_key_bits" => 2048,
"private_key_type" => OPENSSL_KEYTYPE_RSA,
];
$res = openssl_pkey_new($config);
As a rule of thumb, use the cryptographic algorithms and mechanisms that are considered strong by the cryptography community.
The appropriate choices are the following.
The security of these algorithms depends on the difficulty of attacks attempting to solve their underlying mathematical problem.
In general, a minimum key size of 2048 bits is recommended for both. It provides 112 bits of security. A key length of 3072 or 4092 should be preferred when possible.
AES supports three key sizes: 128 bits, 192 bits and 256 bits. The security of the AES algorithm is based on the computational complexity of trying
all possible keys.
A larger key size increases the number of possible keys and makes exhaustive search attacks computationally infeasible.
Therefore, a 256-bit key provides a higher level of security than a 128-bit or 192-bit key.
Currently, a minimum key size of 128 bits is recommended for AES.
Elliptic curve cryptography is also used in various algorithms, such as ECDSA, ECDH, or ECMQV. The length of keys generated with elliptic curve
algorithms is mentioned directly in their names. For example, secp256k1 generates a 256-bits long private key.
Currently, a minimum key size of 224 bits is recommended for EC-based algorithms.
Additionally, some curves that theoretically provide sufficiently long keys are still discouraged. This can be because of a flaw in the curve parameters, a bad overall design, or poor performance. It is generally advised to use a NIST-approved elliptic curve wherever possible. Such curves currently include:
Encrypted data and communications recorded today could be decrypted in the future by an attack from a quantum computer.
It is important to keep
in mind that NIST-approved digital signature schemes, key agreement, and key transport may need to be replaced with secure quantum-resistant (or
"post-quantum") counterpart.
Thus, if data is to remain secure beyond 2030, proactive measures should be taken now to ensure its safety.