程序使用了弱加密算法，無法保證敏感數據的保密性。
陳舊的加密算法（如 DES）再也不能為敏感數據提供足夠的保護了。加密算法依賴于密鑰大小，這是確保加密強度的主要方法之一。加密強度通常通過生成有效密鑰所需的時間和計算能力來衡量。計算能力的提高使得能夠在合理的時間內獲得較小的加密密鑰。例如，在二十世紀七十年代首次開發出該算法時，在 DES 中使用的 56 位密鑰造成了巨大的計算障礙，但今天，使用常用設備能在不到一天的時間內破解 DES。
[1] Standards Mapping - OWASP Top 10 2010 - (OWASP 2010) A7 Insecure Cryptographic Storage
[2] Standards Mapping - OWASP Top 10 2007 - (OWASP 2007) A8 Insecure Cryptographic Storage
[3] Standards Mapping - OWASP Top 10 2004 - (OWASP 2004) A8 Insecure Storage
[4] Standards Mapping - Security Technical Implementation Guide Version 3 - (STIG 3) APP3150.1 CAT II
[5] Standards Mapping - Security Technical Implementation Guide Version 3.4 - (STIG 3.4) APP3150.1 CAT II
[6] Standards Mapping - Common Weakness Enumeration - (CWE) CWE ID 327
[7] distributed.net DES
[8] FAQ About the Electronic Frontier Foundation's "DES Cracker" Machine Electronic Frontier Foundation
[9] Standards Mapping - Web Application Security Consortium 24 + 2 - (WASC 24 + 2) Information Leakage
[10] Mcrypt ciphers The PHP Group
[11] mcrypt_encrypt The PHP Group
[12] Microsoft Security Fundamentals Microsoft
[13] Standards Mapping - FIPS200 - (FISMA) MP
[14] Standards Mapping - SANS Top 25 2009 - (SANS 2009) Porous Defenses - CWE ID 327
[15] Standards Mapping - SANS Top 25 2010 - (SANS 2010) Porous Defenses - CWE ID 327
[16] Standards Mapping - SANS Top 25 2011 - (SANS Top 25 2011) Porous Defenses - CWE ID 327
[17] John Kelsey, Bruce Schneier, and David Wagner Related-key cryptanalysis of 3-WAY, Biham-DES, CAST, DES-X, NewDES, RC2, and TEA
[18] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 - (PCI 1.2) Requirement 6.3.1.3, Requirement 6.5.8
[19] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 - (PCI 2.0) Requirement 6.5.3
[20] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 - (PCI 1.1) Requirement 6.5.8
[21] SDL Development Practices Microsoft