For the cucumber, trim the ends and peel. Cut it in half lengthwise. Remove all the seeds with a small spoon. Cut into 1/8-inch dices. Transfer to a colander. Sprinkle with ¼ teaspoon of salt and toss. Let to drain for 30 minutes. Wrap the cucumbers in 2 layers of paper towels. Squeeze out as much liquid as possible. Pat the cucumber dry with more paper towels.
In a medium bowl, whisk together minced garlic and vinegar. Add yogurt. Mix well. With a spoon, gently fold in the cucumber, dill, 1 teaspoon salt and black pepper. Taste and adjust the seasoning if needed.
Transfer the dip into an air-tight container and keep in the fridge for at least 1 hour before serving.