Wash the cucumbers and pat them dry. Slice them thinly, and place them in a bowl.
Sprinkle salt over the cucumbers and mix well. Let them sit for 10 minutes to draw out excess water.
After 10 minutes, squeeze the cucumbers to remove excess water.
In a separate bowl, mix vinegar, soy sauce, sugar, roasted sesame seeds, minced garlic, Korean chili flakes, sesame oil, and chopped scallions.
Add the cucumber slices to the sauce and mix well.
Serve the Korean cucumber salad chilled.