diff --git a/intelligence_finance_v1_ga/crypto.go b/intelligence_finance_v1_ga/crypto.go
new file mode 100644
index 0000000..cea1d41
--- /dev/null
+++ b/intelligence_finance_v1_ga/crypto.go
@@ -0,0 +1,74 @@
+package intelligence_finance_v1_ga
+
+import (
+	"crypto/hmac"
+	"crypto/rand"
+	"crypto/sha256"
+	"encoding/base64"
+	"fmt"
+	"math/big"
+	"sort"
+	"strings"
+	"time"
+)
+
+// GenerateTimestamp 生成秒级时间戳。
+func GenerateTimestamp() string {
+	return fmt.Sprintf("%d", time.Now().Unix())
+}
+
+// GenerateTimestampMillis 生成毫秒级时间戳。
+func GenerateTimestampMillis() string {
+	return fmt.Sprintf("%d", time.Now().UnixMilli())
+}
+
+// GenerateNonce 生成指定长度的随机字符串（加密安全）。
+func GenerateNonce(length int) (string, error) {
+	const charset = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
+	b := make([]byte, length)
+	for i := range b {
+		num, err := rand.Int(rand.Reader, big.NewInt(int64(len(charset))))
+		if err != nil {
+			return "", err
+		}
+		b[i] = charset[num.Int64()]
+	}
+	return string(b), nil
+}
+
+// HmacSHA256Base64 使用 HmacSHA256 算法对 data 进行签名，密钥为 key，结果 Base64 编码。
+// 对应文档中客户应用签名算法：HmacSHA256，密钥为 client-secret，
+// 签名数据为 x-bfl-signature-timestamp + x-bfl-signature-nonce。
+func HmacSHA256Base64(key, data string) string {
+	h := hmac.New(sha256.New, []byte(key))
+	h.Write([]byte(data))
+	return base64.StdEncoding.EncodeToString(h.Sum(nil))
+}
+
+// BuildSignString 方式1：字典序排序拼接，排除空值与签名字段本身。
+func BuildSignString(params map[string]string) string {
+	keys := make([]string, 0, len(params))
+	for k, v := range params {
+		if v != "" && k != "sign" && k != "signature" {
+			keys = append(keys, k)
+		}
+	}
+	sort.Strings(keys)
+
+	var parts []string
+	for _, k := range keys {
+		parts = append(parts, fmt.Sprintf("%s=%s", k, params[k]))
+	}
+	return strings.Join(parts, "&")
+}
+
+// BuildSignStringOrdered 方式2：固定顺序拼接，排除空值。
+func BuildSignStringOrdered(params map[string]string, orderedKeys []string) string {
+	var parts []string
+	for _, k := range orderedKeys {
+		if v, ok := params[k]; ok && v != "" {
+			parts = append(parts, fmt.Sprintf("%s=%s", k, v))
+		}
+	}
+	return strings.Join(parts, "&")
+}
\ No newline at end of file