缺少簽名意味著無法保證 SOAP 消息的完整性。
消息中任何未經簽名的部分，都可能在發送者或接收者未察覺的情況下被截取和修改。沒有簽名，接收者就無法借助密碼來驗證消息內容來自真正的發送者。
[1] Standards Mapping - OWASP Top 10 2004 - (OWASP 2004) A10 Insecure Configuration Management
[2] Standards Mapping - OWASP Top 10 2010 - (OWASP 2010) A6 Security Misconfiguration
[3] Standards Mapping - FIPS200 - (FISMA) CM
[4] Standards Mapping - Common Weakness Enumeration - (CWE) CWE ID 345
[5] Standards Mapping - Web Application Security Consortium 24 + 2 - (WASC 24 + 2) Insufficient Authentication
[6] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 - (PCI 1.1) Requirement 6.5.10
[7] Web Services Handbook for WebSphere Application Server 6.1 IBM Redbooks