Rule Definition
Insecure use of cryptography is common in most mobile apps that leverage encryption. There are two fundamental ways that broken cryptography is manifested within mobile apps. First, the mobile app may use a process behind the encryption / decryption that is fundamentally flawed and can be exploited by the adversary to decrypt sensitive data. Second, the mobile app may implement or leverage an encryption / decryption algorithm that is weak in nature and can be directly decrypted by the adversary.

Remediation
Better to use the value kCCAlgorithmAES128 instead of kCCAlgorithmDES, kCCAlgorithm3DES, kCCAlgorithmCAST, kCCAlgorithmRC4

Violation Code Sample

CCCrypt(kCCEncrypt,
        kCCAlgorithmDES,
        kCCOptionPKCS7Padding,
        key,
        kCCKeySizeDES, // 64-bit key size
        iv,
        plaintext,
        sizeof(plaintext),
        ciphertext,
        sizeof(ciphertext),
        &numBytesEncrypted);

Fixed Code Sample

CCCrypt(kCCEncrypt,
        kCCAlgorithmAES128,
        kCCOptionPKCS7Padding,
        key,
        kCCKeySizeAES128, // 128-bit key size
        iv,
        plaintext,
        sizeof(plaintext),
        ciphertext,
        sizeof(ciphertext),
        &numBytesEncrypted);

https://www.owasp.org/index.php/Mobile_Top_10_2016-M5-Insufficient_Cryptography